EVER since my first lessons in botany, the characteristic qualities and properties of plants have given me much thought. Why certain plants produced aromatic oils and ethers, while others growing under the same conditions produced special acids or alkaloids, was a subject of endless speculation.
The pleasing aroma of the bark of various trees and shrubs, the spicy qualities of the foliage and seeds of other plants; the intense acridity; the bitterness; the narcotic, the poisonous principle in woody and herbaceous species; all were intensely interesting.
This interest was biological rather than chemical. I cared less for the ultimate composition of the oils, acids, alkalis, etc., than I did for their use or office in the plant economy, and their effect upon those who might use them.
Perhaps no one plant interested me more from this point of view, than the well-known Indian turnip (Arisoema triphyllum). As a boy I was well acquainted with the signally acrid quality of this plant; I was well aware of its effect when chewed, yet I was irresistibly drawn to taste it again and again. It was ever a painful experience, and I suffered the full penalty of my rashness. As an awn from a bearded head of barley will win its disputed way up one's sleeve, and gain a point in advance despite all effort to stop or expel it, so did every resolution, every reflection, counteract the very purpose it was summoned to oppose, and to my sorrow I would taste the drastic, turnip-shaped corm wherever opportunity occurred.
It is a well-known fact that the liquid content of the cells of plants contain numerous inorganic substances in solution. Among these, not considering oxygen, hydrogen, nitrogen and carbon dioxide, there are the salts of calcium, magnesium, potassium, iron, sulphur and phosphorus. The above substances are found in the cells of every living plant. Other substances like salts of sodium and silica are also found, but these are not regarded as essential to the life and growth of plants. They appear to be present because the plant has not the power to reject them. Many of the substances named above, are found deposited either in an amorphous or crystalline form in the substance of the cell wall. In addition to this, crystals of mineral matter, having various shapes and sizes, are often found in the interior of cells. The most common of these interior cell crystals are those composed of calcium oxalate and calcium carbonate. Others composed of calcium phosphate, calcium sulphate and silica are sometimes found. These crystals may occur singly or in clusters of greater or less size. In shape they are prismatic or needle-like.
It is not the object of this paper to treat of plant crystals in general, but to consider the peculiar effect produced by certain forms when found in some well-known plants.
The extreme acridity or intense pungency of the bulbs, stems, leaves and fruit of various species of the Araceae or Arum family, was recognized centuries ago. The cause of this characteristic property or quality was, until a comparatively recent date, not definitely determined.
As far as I am aware the first scientific investigation of this subject was made by the writer. At a meeting of the American Association for the Advancement of Science held at Indianapolis in 1890, some studies and experiments were reported in a short paper entitled "Notes upon the Crystals in certain species of the Arum Family."
This paper expressed the belief that the acridity of the Indian turnip and other plants belonging to the same family, was due to the presence of needle-shaped crystals or raphides found in the cells of these plants. This conclusion was not accepted by Professor T. J. Burrill, of the University of Illinois, nor by other eminent botanists who were present and took part in the discussion that followed the reading of the paper.
The opposition was based mainly on the well-known fact that many other plants like the grape, rhubarb, fuchsia, spiderwort, etc., are not at all, or but slightly acrid, although the raphides are as abundant in them as in the Indian turnip and its allies.
Up to this time the United States Dispensatory and other works on pharmacy, ascribed the following rather indefinite cause for the acridity of the Indian turnip. It was said to be due to an acrid, extremely volatile principle. This principle was insoluble in water and alcohol, but soluble in ether. It was dissipated both by heating and drying, and by this means the acridity is destroyed. There was no opinion given as to the real nature of this so-called principle.
More recently it has been intimated that the acridity may be due to some ferment or enzyme, which has been derived in part from the self-decomposition of protoplasm and in part by the process of oxidation and reduction.
Here the question appeared to rest. At all events I was unable to glean any further knowledge from the sources at my command.
Some time later the subject was taken up in a more comprehensive manner and the following report is the first detailed description of an investigation that has occupied more or less of my leisure for some years.
A dozen or more species of plants have been used for examination and study. Among these were:
Indian turnip (Arisoema triphyllum).Green dragon (Arisoema dracontium).Sweet-flag (Acorus).Skunk cabbage (Spathyema).Calla (Richardia).Caladium (Caladium).Calocasia (Calocasia).Phyllodendron (Phyllodendron).Fuchsia (Fuchsia).Wandering Jew (Tradescantia).Rhubarb (Rheum).Grape (Vitis).Onion (Allium).Horse-radish (Armoracia).
Most of the plants selected were known to have crystals in certain parts. Some of them were known to be intensely acrid. In these the acridity was in every instance proportional to the number of crystals.
The following order of study was pursued and the results of each step noted. Only the more salient points of the methods employed and the conclusions reached are presented.
1. The Character of the Taste Itself.—It was readily noted that the sensation produced by chewing the various acrid plants was quite different. For example, the Indian turnip and its close allies do not give the immediate taste or effect that follows a similar testing of the onion or horse-radish. When the acridity of the former is perceived the sensation is more prickling than acrid.
The effect produced is more like the pricking of numerous needles. It is felt not only upon the tongue and palate, but wherever the part tasted comes into contact with the lips, roof of mouth or any delicate membrane. It is not perceived where this contact does not occur.
The acridity of the onion and horse-radish is perceived at once and often affects other parts than those with which it comes into direct contact.
2. The Acrid Principle Is Not Always Volatile.—This is shown by the fact that large quantities of the mashed or finely grated corms of the Indian turnip and allied species, produced no irritation of the eyes or nose even when these organs were brought into close contact with the freshly pulverized material. This certainly is in marked contrast with the effect produced by freshly grated horse-radish, peeled onions, crushed mustard seed when the same test is applied.
It seems fair to assume that in the latter case some principle that is volatile at ordinary air temperatures is present. The assumption that such principle is present in the former has no room.
In order to test this matter further a considerable quantity of the juice of the Indian turnip was subjected to careful distillation, with the result that no volatile principle or substance of any kind was found.
Various extractive processes were tried by using hot and cold water; alcohol, chloroform, benzene, etc. These failed in every instance to remove any substance that had a taste or effect anything like that found in the fresh Indian turnip.
3. The Acrid Principle Is Not Soluble in Ether.—Inasmuch as various works on pharmacy made the claim that the active or acrid principle of the plants in question was soluble in ether, this was the next subject for investigation. The juice was expressed from a considerable quantity of the mashed Indian turnip. This juice was clear and by test was found to possess the same acrid property as the unmashed corms.
Some of the juice and an equal quantity of ether were placed into a cylinder and well shaken. After waiting until the ether had separated a few drops of the liquid were put into the mouth. For a little time no result was perceived, but as soon as the effect of the ether had passed away the same painful acridity was manifest as was experienced before the treatment with the ether. A natural conclusion from this test was that the acridity might come from some principle soluble in ether.
Observing that the ether was quite turbid and wishing to learn the cause, a drop or two was allowed to evaporate on a glass slide. Examining the residue with a microscope it was found to consist of innumerable raphides or needle-like crystals. Some of the ether was then run through a filter. The filtrate was clear. An examination showed it to be entirely free from raphides, and it had lost every trace of its acridity. The untreated acrid juice of the Indian turnip, calla, and other plants of the same family was then filtered and in every instance the filtered juice was bland and had lost every trace of its acridity. These tests and others that need not be mentioned, proved conclusively that the acridity of various species of the Arum family was not due to a volatile principle, but was due to the needle-shaped crystals found so abundantly in these plants.
Several questions yet remained to be answered. (1) If these needle-like crystals or raphides are the cause of the acridity of the plants just mentioned, why do they not produce the same effect in the fuchsia, tradescantia and other plants where they are known to be just as abundant? (2) Why does the Indian turnip lose its acridity on being heated? (3) Why does the dried Indian turnip lose its acridity?
It was first thought that the raphides found in plants having no acridity, might be of different chemical composition than those which produce this effect.
A chemical examination proved beyond question that the raphides were of the same composition. The needle-shaped crystals in all the plants selected for study were composed of calcium oxalate. The crystals, found in grape, rhubarb, fuchsia and tradescantia were identical in form, fineness and chemical composition with those found in the plants of the Arum family. How then account for the painfully striking effect in one case and the non-effect in the other? This was the perplexing question.
In expressing some juice from the stems and leaves of the fuchsia and tradescantia it was found to be quite unlike that of the Indian turnip and calla. The juice of the latter was clear and limpid; that of the former quite thick and mucilaginous. There was no difference as to the abundance of crystals revealed by the microscope.
After diluting the ropy, mucilaginous juice with water, and shaking it thoroughly with an equal volume of ether, there was no turbidity seen in the supernatent ether. Allowing a few drops of the ether to evaporate scarcely any crystals could be found. Practically none of them had been removed from the insoluble mucilaginous covering. Here and there an isolated specimen was all that could be seen. So closely were these small crystals enveloped with the mucilaginous matter that it was almost impossible to separate or dissect them from it.
It was now easy to explain why certain plants whose cells were crowded with raphides were bland to the taste, while other plants with the same crystals were extremely acrid.
In one case the crystals were neither covered nor embedded in an insoluble mucilage, but were free to move. Thus when the plant was chewed or tasted the sharp points of these needle-like crystals came into contact with the tongue, lips and membranous surface of the mouth.
In the other case the insoluble mucilage which surrounded the crystals prevented all free movement and they produced no irritation.
Why do these intensely acrid, aroid plants lose their acridity on being heated? It is well known that the corms of the Indian turnip and its allies contain a large amount of starch. In subjecting this starch to heat it becomes paste-like in character. This starch paste acts in the same manner as the insoluble mucilage. It prevents the free movement of the crystals and in this way all irritant action is precluded. In heating the Indian turnip and other corms, it was found that the heat applied must be sufficient to change the character of the starch or the so-called acridity was not destroyed.
One other question remains to be answered. It has long been noted that the old or thoroughly dried corms of the Indian turnip are not acrid like those that are fresh. The explanation is simple. As the plant dries or loses its moisture, the walls of the cells collapse and the crystals are closely encased in the hard, rigid matter that surrounds them. This prevents free movement and the crystals can not exert any irritant action.
It is generally believed by biologists that the milky juice, aromatic compounds, alkaloids, etc., found in plants have no direct use in the economy of the plant. They are not connected with the nutritive processes. They are excretions or waste products that the plant has little or no power to throw off. There can be little doubt, however, that these excretory substances often serve as a means of protection. Entomologists have frequently stated that the milky juice and resins found in the stems of various plants act as a protection against stem boring insects. In like manner the bulbs, stems and leaves of plants that are crowded with crystals have a greater immunity from injurious biting insects than plants that are free from crystals. It is quite generally believed that the formation of crystals is a means of eliminating injurious substances from the living part of the plant. These substances may be regarded as remotely analogous to those organic products made by man in the chemical laboratory.
Some progress has been made in this direction, but so far the main results are certain degradation-products such as aniline dyes derived from coal tar; salicylic acid; essences of fruits; etc. Still these and many other discoveries of the same nature do not prove that the laboratory of man can compete with the laboratory of the living plant cell.
Man has the power to break down and simplify complex substances and by so doing produce useful products that will serve his purposes. We may combine and re-combine but so far we only replace more complex by simpler combinations.
The plant alone through its individual cells, and by its living protoplasm has fundamentally creative power. It can build up and restore better than it can eliminate waste products.
SUPPOSE you had a bad case of rheumatism, and your physician came to your bedside and exclaimed loudly, "Hocus pocus, toutus talonteus, vade celeriter jubeo! You are cured." What would you think, what would you do, and what fee would you pay him? Probably, in spite of your aches and pangs, you would make astonishing speed—for a rheumatic person—in proffering him the entire room to himself. But there was a time—and that as late as Shakespeare's day—when so-called doctors in rural England used just such words not only for rheumatism, but for many another disease. And to this hour the fakir on the street corner uses that opening expression, "Hocus pocus." Those words simply prove how slowly the Christian religion was absorbed by ancient Anglo-Saxon paganism; for "Hocus pocus" is but the hastily mumbled syllables of the Catholic priest to his early English congregation—"Hoc est corpus," "this is the body"; and the whole expression used by the old-time doctor meant merely that in the name of the body of Christ he commanded the disease to depart quickly.
How superstitions and ancient rites do persist. To this hour the mountaineers of southwestern Virginia and eastern Tennessee believe that an iron ring on the third finger of the left hand will drive away rheumatism, and to my personal knowledge one fairly intelligent Virginian believed this so devoutly that he actually never suffered with rheumatic pains unless he took off the iron ring he had worn for fifteen years. It is an old, old idea—this faith in the ring-finger. The Egyptians believed that a nerve led straight from it to the heart; the Greeks and Romans held that a blood-vessel called the "vein of love" connected it closely with that organ; and the medieval alchemists always stirred their dangerous mixtures with that finger because, in their belief, it would most quickly indicate the presence of poison. So, too, many an ancient declared that whenever the ring-finger of a sufferer became numb, death was near at hand. Thus in twentieth century civilization we hear echoes of the life that Rameses knew when the Pyramids were building.
Our Anglo-Saxon forefathers had great faith in mysterious words. The less they understood these the more they believed in the curative power. Thus the name of foreign idols and gods brought terror to the local demons that enter one's body, and when Christianity first entered England, and its meanings were but dimly understood, the names of saints, apostles and even the Latin and Greek forms of "God" and "Jesus" were enemies to all germs. Then, too, what comfort a jumbling of many languages brought to the patient, especially if the polyglot cure were expressed in rhythmic lines. Here, for instance, in at least five languages, is a twelfth century cure for gout:
Meu, treu, mor, phor,Teux, za, zor,Phe, lou, chriGe, ze, on.
Perhaps to our forefathers suffering from over-indulgence in the good things of this world, this wondrous group of sounds brought more comfort than the nauseous drugs of the modern practitioner. Any mysterious figure or letter was exceedingly helpful in the sick room of a thousand years ago. The Greek letters "Alpha" and "Omega" had reached England almost as soon as Christianity had, and the old-time doctor triumphantly used them in his pow-wows. Geometric figures in a handful of sand or seeds would prophesy the fate of the ills—and do we not to this day tell our fortune in the geometric figures made by the dregs in our tea-cups? Paternosters, snatches of Latin hymns, bits of early Church ritual were used by quacks of the olden days for much the same reason as the geometric figures—because they were unusual and little understood.
It would have been well had our Anglo-Saxon forefathers confined their healing practices to such gentle homeopathic methods as those mentioned above; but instead desperate remedies were sometimes administered by the determined medicine-man. Diseases were supposed to be caused mainly by demons—probably the ancestors of our present germs—and the physician of Saxon days used all the power of flattery and threat to induce the little monsters to come forth. When the cattle became ill, for instance, the old-time veterinarian shrieked, "Fever, depart; 917,000 angels will pursue you!" If the obstinate cow refused to be cured by such a mild threat, the demons were sometimes whipped out of her, and, if this failed to restore her health, a hole was pierced in her left ear, and her back was struck with a heavy stick until the evil one was compelled to flee through the hole in her ear. Nor was such treatment confined to cattle. The muscular doctors of a thousand years ago claimed they could cure insanity by laying it on lustily with a porpoise-skin whip, or by putting the maniac in a closed room and smoking out the pestering fiends. One did well to retain one's sanity in those good old days.
This use of violent words or deeds in the cure of disease is as ancient almost as the race of man. The early Germans attempted to relieve sprains by reciting confidently how Baldur's horse had been cured by Woden after all the other mighty inhabitants of Valhalla had given up the task, and even earlier tribes of Europe and Asia had used for illness such a formula as: "The great mill stone that is India's is the bruiser of every worm. With that I mash together the worms as grain with a mill stone." Long after Christianity had reached the Anglo- Saxons of England, the sick often hung around their necks an image of Thor's hammer to frighten away the demon germs that sought to destroy the body. This appeal to a superior being was common to all Indo-European races, and the early Christian missionaries wisely did not attempt to stamp out a belief of such antiquity, but merely substituted the names of Christ, the Virgin Mary and the saints for those of the heathen deities. And even into the nineteenth century this ancient form of faith cure persisted; for there are living yet in Cornwall people who heard, as children, this charm for tooth-ache:
Christ passed by his brother's door,Saw his brother lying on the floor;What aileth thee, brother!Pain in the teeth.Thy teeth shall pain thee no more,In the name of the Father, Son and Holy Ghost,I command the pain to be gone.
Let us no longer boast of the carefulness of the modern physician; the ceremonies and directions of the Anglo-Saxon doctor were just as painstaking in minuteness and accuracy. When you feel the evil spirits entering you, immediately seek shelter under a linden tree; for out of linden wood were not battle-shields made? Long before Christianity had brought its gentler touches to English life the tribal medicine man wildly brandished such a shield, and sang defiantly to the witch maidens or disease demons:
Loud were they, lo! loud, as over the land they rode;Fierce of heart were they, as over the hill they rode;Shield thee now thyself, from their spite thou may'st escapethee.Out, little spear, if herein thou be!Underneath the linden stand I, underneath the shining shield,For the might maidens have mustered up their strength,And have sent their spear screaming through the air!Back again to them will I send another,Arrow forth a-flying from the front against them!Out, little spear, if herein thou be!
This business of singing was very necessary in the old time doctor's practice. Sometimes he chanted into the patient's left ear, sometimes into his mouth, and sometimes on some particular finger, and the patient evidently had to get well or die to escape the persistent concerts of his physician. Not infrequently, too, the doctor placed a cross upon the part of one's anatomy to which he was giving the concert, and often the effect was increased by putting other crosses upon the four sides of the house, the fetters and bridles of the patient's horse, and even on the foot prints of the man, or the hoof prints of the beast. Faith in the cross as a charm was unwavering; "the cross of Christ has been hidden and is found," declared the Saxon soothsayer, and by the same token the lost cattle will soon be discovered.
Many and marvelous were the methods to be followed scrupulously by the sick. Cure the stomachache by catching a beetle in both hands and throwing it over the left shoulder with both hands without looking backward. Have you intestinal trouble? Eat mulberries picked with the thumb and ring finger of your left hand. Do you grow old before your time? Drink water drawn silently DOWN STREAM from a brook before daylight. Beware of drawing it upstream; your days will be brief. It reminds one of the practice of the modern herb doctor in peeling the bark of slippery elm DOWN, if you desire your cold to come down out of your head, or peeling it up if you desire the cold to come up out of your chest. One not desiring to place his trust in roots and barks and herbs might turn for aid to the odd numbers, and by reciting an incantation three or seven or nine times might not only regain health, but recover his lost possessions. Or the sufferer might transfer his disease by pressing a bird or small animal to the diseased part and hastily driving the creature away. The ever-willing and convenient family dog might be brought into service on such an occasion by being fed a cake made of barley meal and the sick man's saliva, or by being fastened with a string to a mandrake root, which, when thus pulled from the ground, tore the demon out of the patient.
The cure of children was a comparatively easy task for the Anglo-Saxon doctor; for the only thing to be done was to have the youngster crawl through a hole in a tree, the rim of the hole thus kindly taking to itself all the germs or demons. So, too, minor sores, warts and other blemishes might easily be effaced by stealing some meat, rubbing the spot with it, and burying the meat; as the meat decayed the blemish disappeared. So to this day some Indians, and not a few Mexicans make a waxen image of the diseased part, and place it before the fire to melt as a symbol of the gradual waning of the illness. So, too, the ancient Celts are said to have destroyed the life of an enemy by allowing his waxen image to melt before the fire.
To cure a dangerous disease or the illness of a full-grown man was, however, a much more difficult matter. Inflammation, for instance, was the work of a stubborn demon, and stubborn, therefore, must be the strife with him. Hence, dig around a sorrel plant, sing three paternosters, pull up the plant, sing "Sed libera nos a malo," pound five slices of the plant with seven pepper corns, chant the psalm "Misere mei, Deus" twelve times, sing "Gloria in excelsis, Deo," recite another paternoster, at daybreak add wine to the plant and pepper corns, face the east at mid-morning, make the sign of the cross, turn from the east to the south to the west, and then drink the mixture. Doubtless by this time the patient had forgotten that he ever possessed inflammation.
Long did the superstitions in medicine persist. In Chaucer's day, the fourteenth century, violent and poisonous drugs were used, but luckily they were often administered to a little dummy which the doctor carried about with him. As we read each day in our newspapers of the various nostrums advertised as curing every mortal ill, we may well wonder if the average credulity has really greatly lessened after twelve centuries of fakes and faith cures, and we almost long for the return of the day when the medicine man practiced on a dummy instead of the human body.
THE article entitled "The Racial Origin of Successful Americans," by Dr. Frederick Adams Woods, which appeared in the April (1914) issue of The Popular Science Monthly, set forth some very interesting and instructive results. The methods used to arrive at these results, however, do not seem to be such as to establish them as final and conclusive.
It is not sufficient to consider merely the number of persons bearing certain names in "Who's Who in America," for the purpose of establishing the relative capability of various nationalities. The percentage of the number bearing that name in the city in question is the significant figure.
The writer has, therefore, taken the directories[1] of the four American cities, which were the subjects of study in the original article, and has estimated the number of persons of a certain name living in each city by first counting the number of names printed in a whole column of the directory and then multiplying this figure by the number of columns occupied by that name. The number of persons bearing the same name in "Who's Who in America" (1912-1913) is then taken for each city. The percentage is finally calculated of the number of the "Who's Who in America" names in the number of those bearing that name in the directories.
[1] (1) Trow's General Directory—Boroughs of Manhattan and Bronx, City of New York, 1913. Trow Directory, Printing & Bookbinding Company, Pub. (2) Boyd's Philadelphia City Directory, 1913. C. E. Howe Company, Pub. (3) The Lakeside Annual Directory of the City of Chicago, 1913. Chicago Directory Company, Pub. (4) The Boston Directory, 1913. Simpson and Murdock Co., Publishers.
It seems best, furthermore, to narrow down the consideration from the fifty most common names in each city to only those of this number which are common to all four cities in order that any one family may not have too great a weight. The names in each city are then arranged according to the established percentages.
The grouping of names as an indication of race or nationality is taken from Robert E. Matheson's "Surnames in Ireland." It is found to agree exactly with the grouping in the article by Dr. Woods, who classified them from the table given in the New York World Almanac and Encyclopedia for 1914, which table was, no doubt, compiled from Matheson.
New York (Exclusive of Brooklyn)E White 1.39%E Williams 1.18E Clark 1.05E Taylor 1.02E Jones 0.89E Martin 0.87E Smith 0.78E Thompson 0.74E-Sc-G Miller 0.73E Wilson 0.71E Brown 0.70E-Sc Moore 0.60E Davis 0.59E-Sn Johnson 0.56Sc-Sn Anderson 0.55I Murphy 0.46I Kelly 0.37E Klien 0.24E Hall 0.23Sc Campbell 0.17I O'Brien 0.14E Lewis 0.12E-Sc Young 0.10
Nationality Averages
G German 0.73%E English 0.69Sn Scandinavian 0.55Sc Scotch 0.43I Irish 0.32
ChicagoE Hall 0.72E-So Moore 0.41E Wilson 0.35E Davis 0.27E-Sc Young 0.27E Thompson 0.26E Brown 0.22E Lewis 0.20E Taylor 0.17E-Sc-G Miller 0.17E Martin 0.16I Kelly 0.16E Williams 0.15E White 0.14E Clark 0.14E Smith 0.14E Allen 0.13Sc Campbell 0.11E Jones 0.10E-Sn Johnson 0.06I Murphy 0.06Sn-ScAnderson 0.05I O'Brien 0.00
Nationality Averages
E English 0.22%Sc Scotch 0.20G German 0.17I Irish 0.11Sn Scandinavian 0.05
PhiladelphiaE White 0.46%E Lewis 0.32E Taylor 0.31E Wilson 0.30E Jones 0.27E-Sn Johnson 0.23E Williams 0.22E-Sc Moore 0.20E Davis 0.18E-Sc Young 0.18E Clark 0.14E Smith 0.13E Brown 0.13E-Sc-G Miller 0.12E Martin 0.08E Thompson 0.08I Murphy 0.08Sc Campbell 0.08Sn-Sc Anderson 0.00I Kelly 0.00E Allen 0.00E Hall 0.00I O'Brien 0.00
Nationality AveragesE English 0.18%Sn Scandinavian 0.16G German 0.12Sc Scotch 0.11I Irish 0.02
BostonE Allen 0.72E Williams 0.67E Brown 0.61E Hall 0.43E Campbell 0.33E Clark 0.30E Smith 0.29E Thompson 0.28E Taylor 0.25Sn-Sc Anderson 0.22E Lewis 0.20E-Sn Johnson 0.19E White 0.18E-Sc Moore 0.17E Wilson 0.13E Jones 0.11I O'Brien 0.08I Murphy 0.05E Martin 0.00E-Sc-G Miller 0.00E Davis 0.00I Kelly 0.00E-Sc Young 0.00
Nationality Averages
E English 0.25Sn Scandinavian 0.20Sc Scotch 0.14I Irish 0.06G German 0.0?
Name Averages
E Williams 0.55E White 0.54E Taylor 0.44E Brown 0.41E Clark 0.40E Wilson 0.37E Jones 0.34E Thompson 0.34E-Sc Moore 0.34E Hall 0.34E Smith 0.33E Martin 0.27E Allen 0.27E Davis 0.26E-Sn Johnson 0.26E-Sc-G Miller 0.25E Lewis 0.21Sn-Sc Anderson 0.20Sc Campbell 0.17I Murphy 0.16E-Sc Young 0.14I Kelly 0.13I O'Brien 0.05
Nationality AveragesE English 0.34G German 0.25Sn Scandinavian 0.24Sc Scotch 0.22I Irish 0.12
The nationality attributed to each name is indicated in the tables below by capital letters in the parallel columns. In some cases a name is shared by two or even three nationalities. The percentages belonging to such names are attributed to each of the sharing nationalities in making the final averages. This, of course, is a serious source of error, since the division of such names among the nationalities is not known. No stress can be laid on our figures for the German, Scotch and Scandinavian nationalities, because they contain so many of these indecisive names.
The names in each city are then arranged in groups according to their nationality and averages computed from the percentages established for each name. These averages, which appear at the bottom of each column, give a fair estimation of the capability of the different nationalities, but are, nevertheless, open to a few minor errors. For instance, the Germans head the list in New York with 0.73 per cent. for only one third of a single name, while the English rank second with a total of 15 5/6 names. The final averages for nationality, however, which appear at the bottom of the fifth column and which are made from the averages computed for each city, partly eliminate this error and place the groups in their proper rank.
In order to make the results more conclusive, general averages are drawn for each name from the percentages established for that name in all four cities and are placed in the fifth column according to their rank. Final averages of percentages for nationalities are then made from this column, just as they were for each city. The results obtained agree exactly with the final averages made before and, therefore, are placed coincident with them at the bottom of the fifth column.
The results finally arrived at seem to corroborate the conclusions of Dr. Wood; namely, that in the four leading American cities, New York, Chicago, Philadelphia and Boston, "those of the English (and Scotch) ancestry are distinctly in possession of the leading positions, at least from the standpoint of being widely known." Yet it does not seem safe to disregard entirely those other nationalities which rank so closely with the English merely because of the small number of them included in our consideration; for, as has been stated above, we do not know what proportion of a certain name to attribute to various nationalities.
There is one serious, but unavoidable, source of error, moreover, which has apparently been overlooked. The conclusions as to the relative intelligence of various races are drawn from the number of names, belonging to these races, which appeared in "Who's Who in America." According to the standards of this compilation, eminence is very largely dependent upon education, which does not give the emigrants, who are too poor to get proper education, an equal opportunity to display their intellectual power and, therefore, to be considered in the above calculations. Races that immigrated predominantly in the last century will be less handicapped than those which have only recently immigrated in large numbers. It is very difficult, however to know how much weight to place upon this modifying influence.
Another source of error is the fact that certain nationalities or races seem to have natural inclinations and desires to follow in disproportionate numbers one kind of activity or occupation and are content to let other people rise to those positions which make them "the best-known men and women of the United States." As Dr. Woods states, the Jews could not be expected to show as large a percentage, since they largely turn their attention to the banking, wholesale and retail trades, in which they have been very successful, but in which eminence is not correspondingly recognized in "Who's Who in America."
No comment is made on Jewish achievement, however, because no Jewish name is among the fifty most common in all four cities, and hence there are not enough numbers for study. But the Irish, by their traditional devotion to politics and their success in attaining the lower ranks of political leadership, would seem to be in line for recognition in large numbers, which they nevertheless do not attain.
In spite of these qualifications, however, it becomes apparent that the statistics above established can not be rejected. Although they do not exactly justify Dr. Woods's conclusions, they at least show that the intellectual achievements of different races vary. They also show that a much more extensive study of the subject must be made before any conclusions can be established as final.
We believe, therefore, that Dr. Woods's conclusion—that "there have been a few notable exceptions, but broadly speaking all our very capable men of the present day have been engendered from the Anglo-Saxon element already here before the beginning of the nineteenth century"—should be modified. A sounder conclusion and, in fact, the only one that could be reached through the results established above, would be this: Achievement in those activities represented in "Who's Who in America" is acquired disproportionately by stocks predominantly Teutonic in comparison with the Irish.
AS the Rhine broadens on its approach to the Lake of Constance or Boden Sea it flows through a region made classic by the researches of scientific men. Here at low tide it is sometimes possible to see wooden piles which in prehistoric times supported the houses of the lake-dwelling folk, whose work is so well represented in various museums, especially at Zurich. From the river, on each side, the land rises rapidly, and the rounded summits of the hills are well wooded. It is on the left side of the Rhine, about two and a half miles below the town of Stein, that we come to the famous locality for Miocene fossils, the European representative of our Florissant in Colorado.
In all the books the fossil beds are said to be at Oeningen, which is the name of a once celebrated Augustinian monastery about two miles away. Actually, however, the locality is above the village of Wangen, which is situated on the north bank of the river. In some quite recent writings Oeningen (Wangen) is referred to as being in Switzerland; it is in Baden, though the opposite bank of the Rhine is Swiss. The error is natural, since the fossils have chiefly been made known by the great Swiss paleontologist Heer, of Zurich, and the best general account of them is to be found in his book "The Primaeval World of Switzerland," of which an excellent English translation appeared in 1876.
It was at the Oeningen quarries, in the eighteenth century, that a wonderful vertebrate fossil, some four feet long, was discovered. A writer of that period, Scheuchzer, announced it as Homo diluvii testis, a man witness of the deluge! Cuvier knew better, and was able to demonstrate its relationship to the giant salamanders of Eastern Asia and North America. It forms, in fact, a distinct genus of Cryptobranchidae, which Tschudi, apparently mindful of the early error, named Andrias; though the proper name of the animal appears to be Proteocordylus scheuchzeri (Holl.). The stone at Wangen was used for building purposes, and at one time there were three or four quarries actively worked. In earlier times the larger fossils naturally attracted most attention, fishes, snakes, turtles, fresh-water clams and a variety of leaves and fruits. Such specimens were saved, and were sold and distributed to many museums. The supply was good, yet at times not sufficient for the market; so the monks at Oeningen, and others, would carve artificial fossils out of the soft rock, coating them with a brown stain prepared from unripe walnut shells. In later years, during the middle part of the nineteenth century, the period of Darwin, the great importance and interest of the fossil beds came to be better appreciated. Dr. Oswald Heer, professor at Zurich, an accomplished botanist and entomologist, did perhaps nine tenths of the work, describing plants, insects, arachnids and part of the Crustacea. The fishes were described by Agassiz, and later by Winkler. The remaining vertebrates were principally made known by E. von Meyer.
From 1847 to 1853 Heer published in three parts a great work on fossil insects, largely concerned with those from Oeningen.[1] In this and later writings he made known 464 species from this locality; but in the latest edition of "The Primaeval World of Switzerland" it is stated that there are 844 species, 384 of these being supposedly new, and named, if at all, only in manuscript.
[1] "Die Insektenfauna der Tertiargebilde von Oeningen und von Radoboj in Croatien" (Leipzig: Engelmann).
My wife and I, having worked a number of years at Florissant, were very anxious to see the corresponding European locality for fossil insects. The opportunity came in 1909, when we were able to make a short visit to Switzerland after attending the Darwin celebration at Cambridge. We went first to Zurich, where in a large hall in the University or Polytechnicum we saw Heer's collections. A bust of Heer stands in one corner, while one end of the room is covered by a large painting by Professor Holzhalb, representing a scene at Oeningen as it may have appeared in Miocene times, showing a lake with abundant vegetation on its shores, and appropriate animals in the foreground. Numerous glass-covered cases contain the magnificent series of fossils, both plants and animals. Dr. Albert Heim, professor of geology and director of the Geological Museum, was most kind in showing us all we wanted to see, and giving advice concerning the precise locality of the fossil beds. Professor Heim is an exceedingly active and able geologist, but neither he nor any one else has continued the work of Heer, whose collections remain apparently as he left them. The 384 supposedly new insects are still undescribed, with a few possible exceptions. I had time only to critically examine the bees, of which I found three ostensibly new forms. Of these, one turned out to be a wasp,[2] one was unrecognizable, but the third was a valid new species, and was published later in The Entomologist. There can be no doubt that Heer was too ready to distinguish species of insects in fossils which were so poorly preserved as to be practically worthless, consequently part of those he published and many of those he left unpublished will have to be rejected. Nevertheless, the Oeningen materials are extremely valuable, both for the number of species and the good preservation of some of them. All should be carefully reexamined, and the entomologist who will give his time to this work will certainly be rewarded by many interesting discoveries.
[2] Polistes, or very closely related to that genus.
Provided with instructions from Professor Heim, we started on August 4 for Wangen, going by way of Constance. Thanks to the map furnished by the Swiss railroad, we had no difficulty in finding the Rosegarten Museum in Constance, which contains so many interesting fossils and archeological specimens from the surrounding region. At the moment we arrived, the old man in charge was about to go to lunch, and we were assured that it was impossible to get into the museum. It was then or never for us, however; and when the necessary argument had been presented, the curator not only let us in, but remained with us to point out all the objects of interest, showing a great deal of pride in the collection. The series of Oeningen fossils could not, of course, rival that at Zurich; but it contained a great many remarkable things, including some excellent insects. We then boarded the river steamer, and, passing through the Unter Sea, reached the small village of Wangen in the course of the afternoon. This is not a tourist resort of any consequence; the local guide book refers to it as follows: "Wangen (with synagogue). Half an hour to the east is the Castle of Marbach, now a well-appointed sanatorium for disorders of the nerves and heart. To the west the romantic citadel Kattenhorn, formerly used as a rendezvous by notorious highwaymen (at present in the possession of a pensioned off German officer)." The guide continues, calling our attention to "Oberstaad. Formerly a castle, now a weaving mill for hose. Above it (448 meters) the former celebrated Augustine monastery Oehningen. Near by interesting and curious STONE FOSSILS are found." Thus the visitor is likely to be misled as to the whereabouts of the fossils, the tradition that they are at Oeningen having misled the author of the guide. At Wangen we found a small but most excellent hotel conducted by George Brauer, where we hastily secured a room, and went out to hunt the fossil beds. We were to walk over half an hour northward, up the hill, and look for the quarries near the top of the high terrace above the village. This we did, but at first without result. We passed a small grassy pit, where some of the rock was visible, but it did not look at all promising. We went back and forth, and up the hill, until we were practically on the top. The country was beautiful, and by the roadside we found magnificent red slugs (Arion ater var. lamarckii[3]) and many fine snails, including the so-called Roman snail, Helix pomatia. We accosted the peasants, and enquired about the "fossilen." The word seemed to have no meaning for them, so we tried to elucidate it in the manner of the guide: where were the "stein fossilen"? Immediately, with animation, we were shown a road going westward to the town of Stein, where, it was naturally assumed, the object of our enquiry would be found. Quite discouraged, we wandered down the hill until we came to the pit we had noticed when going up. Close by was a neat little cottage, and it occurred to us to try our luck there as a last resort. We were glad indeed when there appeared at the door an educated man, who in excellent Shakespearian English volunteered at once to show us the fossil beds. It was Dr. Ernst Bacmeister, a man of considerable note in his own country, whose life and deeds are duly recorded in "Wer ist's?" He came, with his wife and child, to Wangen in the summer time, to enjoy these exquisite surroundings, where he could write happily on philosophical subjects, without much danger of interruption. Dr. Bacmeister informed us that the poor little pit close by was in fact one of the noted quarries, with the sides fallen in and the debris overgrown with herbage. A short distance away we were shown the others, in the same discouraging condition.
[3] The earliest name for this richly colored variety is Limax coccineus Gistel, but it is not Limax coccineus Martyn, 1784; so the next name, lamarckii, prevails.
One could see that there had once been considerable excavations, but the good layers were now deeply covered by talus, and could only be exposed after much digging. It was about thirty years since the pits had been worked. Dr. Bacmeister found for us a strong country youth, Max Deschle, who dug under our direction all next day in the quarry near the house. The rock is not so easy to work as that at Florissant, and it does not split so well into slabs, but we readily found a number of fossils. Most numerous were the plants; leaves of cinnamon (Cinnamomurn polymorphum), soapberry (Sapindus falcifolius), maple (Acer trilobatum), grass (Poacites loevis) and reeds (Phragmites oeningensis), with twigs of the conifer Glyptostrobus europoeus. We obtained a single seed of the very characteristic Podogonium knorrii. Certain molluscs were abundant; Planorbis declivis, Lymnoea pachygaster, Pisidium priscum, with occasional fragments of the mussel Anodonta lavateri. Ostracods, Cypris faba, were also found. The best find, however, was a well-preserved fish, the lepidocottus brevis (Agassiz), showing in the region of the stomach its last meal, of Planorbis declivis. This greatly interested Max, who during the rest of the day chanted, as he swung the pick, "Fischlein, Fischlein, komme!"—but no other Fischlein was apparently within hearing distance. Not a single insect was obtained, except that on the talus at one of the other quarries I picked up a poorly preserved beetle, apparently the Nitidula melanaria of Heer.
We left Wangen on the morning of August 6, and proceeded up the Rhine to Schaffhausen and Basle. At Basle we found a certain number of Oeningen (Wangen) fossils in the museum.
Comparing Wangen with Florissant, it appears that the Colorado locality is more extensive, more easily worked, and provides many more well-preserved fossils. On the other hand, Wangen has proved far richer in vertebrates and crustacea, and on the whole gives us a better idea of the fauna as it must have existed. Florissant far exceeds Wangen in the number of described species, but this is only because it has so many more insects. Each locality furnishes us with extraordinarily rich materials, enabling us to picture the life of Miocene times. Each, by comparison, throws light on the other, and while the period represented is not sufficiently remote to show much evidence of progressive evolution, it is hard to exaggerate the value of the facts for students of geographical distribution. Much light may also be thrown on the relative stability of specific characters.
Work on the Florissant fauna is going forward, though not so fast as one could wish. It is very much to be hoped that the Wangen quarries will receive attention before many years have passed. Labor is comparatively cheap in Germany, and with a force of a dozen men it would not take long to open up the quarries and get at the best beds. It is really extraordinary that no one has seen and taken advantage of the opportunities presented. Probably no obstacles of any consequence would be put in the way; at least the owner of the quarries came by when we were digging, and expressed only his good will. With new researches in the field, combined with studies of the rich materials awaiting examination at Zurich and elsewhere, no doubt the knowledge we possess of the European Miocene fauna could be very greatly increased, to the advantage of all students of Tertiary life.
[1] Some of the instruments used were obtained through a grant from the Elizabeth Thompson Science Fund.
BY ALEXANDER McADIE
ONLY in recent years have aerologists given much attention to the slow-moving currents of the lower strata of the atmosphere. These differ greatly from the whirls and cataracts of both low and high levels which we familiarly know as the winds. The upper and larger air streams play a part in the formation of frost, and we do not underestimate their function; but primarily it is a slow surface flow, almost a creeping of the air near the ground, which controls the temperature and is all-important in frost formation. So important is it that the first law of frost fighting may be expressed as follows:
Where air is in motion and where there is good circulation, frost is not so likely to occur as where the air is stagnant.
In other words frost in the ordinary meaning of the word is a problem IN LOCAL AIR DRAINAGE. It is true that there are times when with thorough ventilation and mixing of the air strata the temperature will fall rapidly and damage from frost result; but such conditions are perhaps more fittingly described as cold waves or freezes, as distinguished from frosts. Thus, in California during the first week of January, 1913, when there was much air movement, the citrus fruit crop was damaged to the extent of $20,000,000. The condition is generally referred to as a frost, but it was quite different from the usual frost conditions in that section. It is, however, interesting to note that improved frost-fighting devices were used with much success and the total savings aggregated about $25,000,000. The orange growers also had the benefit of accurate forecasts and expert advice and were thus able to provide fuel and labor in advance. Passing over at present the larger disturbances, we shall consider only the frosts of still nights. And it should not be forgotten that the accumulated losses of these frosts may equal the losses of the individual freezes, for the latter occur at long intervals, while the quiet frosts of the early fall and the late spring are recurrent, destroying flowers, fruits and tender vegetation in many sections, year after year.
Air may flow in any direction, but attention has been centered more upon the flow in a horizontal than in a vertical direction. Thus none of the wind instruments used at Weather Bureau stations gives any record of the up and down movement of the air. In frosts of the usual type this vertical displacement is all-important. True, there may be brought into the district, by horizontal displacement, large masses of cold air and the temperature thus materially lowered; but the marked INVERSION of temperature occurs only when these horizontal currents or winds are lulled. On windy nights, as is well known, there is less likelihood of frost than on quiet nights, because of the thorough mixing of the air vertically. There is then no tendency for stratification and the formation of levels of different temperature, followed by low surface temperature.
In general, the temperature falls as one rises in the air; but, at times of frost, it is found that the higher levels are warmer than the lower ones. The coldest stratum is found about ten centimeters (four inches) above the ground; while at a distance of ten meters temperatures are as much as five degrees higher than at the ground.
It may be well to refer for a moment to the variations in temperature known as inversions. In the accompanying diagram it will be seen that the temperature falls with elevation, and starting from the ground on a day when the temperature is near the freezing point, 273 degrees A., one finds at a height of seven thousand meters a fall of about forty degrees. It is not easy to represent on a single diagram the variation in detail and therefore we have divided the air column into three parts, the scales being as one to a hundred.
The right-hand diagram shows the gradual rise in temperature for a height of one meter and the peculiar inversion that occurs a few centimeters above the ground. Unfortunately it is in this layer where detailed temperature observations are most needed that our instruments are least satisfactory. Ordinary thermometers can not be relied on for such small differences and the exploration of this stratum by self-recording instruments is difficult. In the middle diagram is shown the temperature gradient at times of frost, from the ground to a height of one hundred meters. It will be seen that at a height of fifty meters the temperature may be ten degrees higher; and in general the rise continues with elevation. A good illustration of a valley inversion is given by the chart of May 20, in which continuous records for three levels, 18, 64 and 196 meters above sea level, are given. At such times fruit or flowers on hillsides escape damage from frost while in all the depressions and low level places the injury may be marked. These differences in temperature are not at all unusual and may be anticipated on clear, still nights during spring, fall and winter. Clouds or a moderate wind will prevent such an inversion. We shall refer again to this in speaking of the cranberry bogs of the Cape Cod district and the frost warnings issued from Blue Hill Observatory.
The great inversion in the atmosphere, however, is that which we have indicated as occurring at the height of nine thousand meters. Above this, the temperature ceases to fall and we enter what has been called the stratosphere or isothermal region. For convenience we will call this upper change the MAJOR inversion and the lower one near the ground the MINOR inversion. In some ways we know more about the former than the latter. Strictly speaking, the minor inversion is the chief factor in determining local climate since it controls night and early morning temperatures and in large measure the early or late blooming of flowers and ripening of fruits.
Ordinarily cold air falls to the ground; but not always, for under certain conditions cold, heavy air may actually rise, displacing warm, lighter air. But such conditions can be explained and there is no contradiction of the fundamental law that if acted on only by gravity, cold air, being denser, will settle to the ground and warm air, being lighter, will rise. And there must be a certain relation between the height of the level from which the cold air falls and the level to which the warm air rises. In other words, we have to apply the laws of falling bodies since a given mass of air, although invisible, is matter and as subject to gravity as a cannon ball.
One of Galileo's most ingenious experiments consisted in swinging a pendulum and then by means of a nail driven in various positions intercepting the swing. He found that the bob always rose to the same level whatever circuit it was forced to take. But Galileo did not know what every schoolboy to-day knows, that air exerts pressure and is subject to physical processes like other matter, else he would certainly have given to the world a delicate air pendulum; and devised experiments on the movement of air that would have opened men's eyes to the fascinating flow and counter-flow of the air, even on a seemingly still night, one favorable for the formation of frost.
The problem of the moving air mass, however, is more complicated than it looks. For with the air is mixed a quantity of water vapor. In a strict sense they are independent variables, and the view set forth in most text-books that air has a certain capacity for water vapor is misleading. We seldom meet with pure, dry air. A cubic meter of such a gas mixture would weigh 1,247 grams, at a temperature of 283 degrees A. (50 degrees F.). If chilled ten degrees, that is, to the freezing point of water, it would weigh 46 grams more. So that by cooling, air becomes denser and heavier. A cubic meter of a mixture of air and water vapor at saturation, at the first temperature above mentioned weighs only 1,242 grams, or five grams less, and if this were cooled ten degrees the mixture would weigh three grams less than the same volume of pure dry air. We see that in each case the mixture of air and water vapor weighs less than the air by itself. One would think that by adding water vapor which, while light, still has weight, the total weight would be the sum of both. It really is so, notwithstanding the above figures, and the explanation of the puzzle is that there was an increase in pressure with expansion, so that the volume of the air and saturated vapor was greater than one cubic meter. Since then a cubic meter of air and saturated vapor weighs less than a cubic meter of dry air at freezing temperature, speaking generally, we may expect moist air to rise and dry air to fall. Consequently, if in addition to falling temperature there is also a drying of the air, we shall have an accelerated settling or falling of cold dry air to the ground, which of course favors the formation of frost. The water vapor plays also another role besides that of varying the weight per unit volume. The heat received by the ground consists of waves of a certain wavelength; but the heat re-radiated by the ground consists of waves of longer wave-length, and these so-called long waves (12 thousandths of a millimeter) are readily absorbed by water vapor. Thus water vapor acts like a blanket and holds the heat, preventing loss of heat by radiation to space. Further on we shall speak of the high specific heat of both water and water vapor as compared with air and show the bearing of this in frost fighting; but at present we may from what precedes formulate the second law of frost fighting as follows: "Frost is more likely to occur where the air is dry than where it is moist." It is also true that a dusty atmosphere is less favorable for frost than a dust-free atmosphere. Thus we may generalize and say that whatever favors clear, still, dry air favors frost. The theory of successful frost fighting then is to interfere with or prevent these processes which as we have seen facilitate cooling close to the ground. In what way can this best be done?
The most natural way would be by conserving the earth's heat, which could be accomplished by covering plants with cloth, straw, newspaper, or perhaps better still, modern weather-proof sheeting, or in still another way by a cover of moistened dense smoke, generally called a smudge. A second method would be by means of direct application of heat; and this is accomplished in orange groves by means of improved orchard heaters. Large fires waste heat and are neither economical nor effective. A third method would be based upon a mixing of the air strata, thus getting the benefit of the warmer higher levels. Fourth, advantage might be taken of some agency such as water or water vapor, having a high specific heat. Finally, if the crop is of a certain character such as the cranberry, it will be found advisable to use sand, to drain and clean, here again making use of the specific heat of some intermediary. And, furthermore, any one of these methods may be combined with some other method.
Regarding the first method, that of covers, it may be said that the practice goes back to the early husbandmen; but only in the last few years has the true function of the cover been properly interpreted and we are still far from obtaining maximum efficiency. Nor is there yet a suitable, scientific cover available. Any medium that interferes with loss of heat through free radiation before and after sunset is a cover. The best type of cover is a cloud; and clouds, whether high or low, are good frost protectors. On cloudy nights there is little likelihood of frost; and when we can bring about the formation of a layer of condensed water vapor we can practically eliminate frost. We have mentioned above the fact that the earth radiates the heat it has received not in the same but in longer wave-lengths perhaps three times as long. These are easily trapped and held by the vapor of water. Furthermore, the rate of radiation is a function of the absolute temperature and so the rapidity of loss depends somewhat upon the heat received. Therefore the cover should be used as early in the afternoon as possible, that is just before sunset. Aside from the water cover or vapor cover there are cheap cloth screens, fiber screens and in some places lath screens.
The second method, that of direct heating, has met with much success in the orange groves of California and elsewhere. Modern heating and covering methods date from experiments begun in 1895. A number of basic patents granted to the writer in this connection have been dedicated to the public. At the present time there are on the market some twenty forms of heaters, which have been described with more or less detail in farm journals and official publications. It is not necessary to refer to them further here. The fuel originally used was wood, straw and coal, but these are now supplanted by crude oil or distillate. It has also been seriously proposed to use electric heaters; also to use gas in the groves. With modern orchard heaters properly installed and handled, there is no difficulty in raising the temperature of even comparatively large tracts five degrees and maintaining a temperature above freezing, thus preventing refrigeration of plant tissue.
The third method, that of utilizing the heat of higher levels by mixing, has not yet been commercially developed; but the methods of applying water, either in the spraying of trees or the running of ditches or the flooding of bogs, together with methods of sanding, cleaning; and draining, have all been proved helpful. Methods available and most effective in one section may not necessarily be effective in another section or with different crop requirements. Certain devices most effective in the groves of California may not answer in Florida or Louisiana because of entirely different weather conditions. In the Gulf coast states where water is available it may be advantageously used to hold back ripening and retard development until after the cold waves of middle and late February have passed, whereas in the west coast sections conditions are very different, water having a definite value and the critical periods coming in late December or early January.
In what precedes stress has been laid chiefly upon the fall of temperature and the congelation of the water vapor. There is, however, another important matter connected with injury to plant tissue, and that is the rise in temperature AFTER the frost. A too rapid defrosting may do considerable damage where no damage was originally done by the low temperature. It is in this connection that water may be used to great advantage. Water, water-vapor and ice have, compared with other substances, remarkably high specific heats. If the specific heat under constant pressure of water be taken as unity, that of ice is 0.49; of water-vapor 0.45 and of air 0.24. Or in a general way we may say that water has four times the capacity for heat that air has. Therefore it is apparent that water will serve excellently to prevent rapid change in temperature. This is important at sunrise and shortly after when some portion of the chilled plant tissue may be exposed to a warming sufficient to raise the temperature of the exposed portion ten degrees in an hour. The latent heat of fusion of ice is 79.6 calories and the latent heat of vaporization of water is nearly 600 calories (a gram calorie is the amount of heat that will raise the temperature of a gram of pure water one degree) or in exact terms from 273 degrees A. to 274 degrees A. Therefore in the process of changing from solid to liquid to vapor, as from ice to water to vapor, there is a large amount of heat required. The latent heat serves to prevent fall in temperature and also serves to retard a too rapid rise. This does not mean, as is generally assumed, that the air will be warmed, but it does mean a retardation of temperature change. And it is essential that the restoration of the tissues and juices to their normal state be accomplished gradually, neither too rapidly nor yet too slowly.
There is probably an optimum temperature for thawing or defrosting frozen fruits and flowers. Finally the temperature records as ordinarily obtained need careful interpretation. It may be that the freezing point of liquids under pressure in the plant cells or exposed to the air through the stomata is not the same as in the free air. It is unfortunate too that in most places data showing temperatures of soil, plant and air are of doubtful character. A word of warning may be given against the too ready acceptance of Weather Bureau records made in cities and on the roofs of buildings. Garden and field conditions vary greatly from these. It is further advisable to obtain a continuous record of the temperature of evaporation such as is shown by the records herewith. The two temperature curves made simultaneously and easily read at any moment enable the gardener or orchardist to forecast the probable minimum temperature of the ensuing ten or twelve hours. But not always, and some study is necessary. A slight increase in cloudiness or a slight shift in wind direction will prevent the fall in temperature which otherwise seemed probable. With a persistent inversion of temperature there is sometimes an increasing absolute humidity.
The problem is many sided and we must consider the motion of the air vertically as well as horizontally. Air gains and loses heat chiefly by convection, and any gain or loss by conduction may be neglected. The plant gains heat by convection, radiation and perhaps by conduction of an internal rather than surface character. The ground gains and loses heat chiefly by radiation. But the whole process is complicated and may not even be uniform. Frosts generally are preceded by a loss of heat from the lower air strata, due to convection and a horizontal translation of the air. Then follows an equally rapid and great loss of heat by free radiation. There are minor changes such as the setting free of heat in condensation and the utilization in evaporation, but these latent heats are of less importance than the actual transference of the air and vapor and the removal of the latter as an absorber and retainer of heat.
Frosts are recurrent phenomena reasonably certain to occur within given dates, and, as pointed out above, the cumulative losses are considerable. Methods of protection to be serviceable must be available for more than one occasion, for there is no profit in saving a crop on one night and losing it on the succeeding night. But the effort is worth while. Consider that the horticulturist regularly risks the labor of many months on the temperatures of a few hours. An efficient frost fighting device is in a way the entering wedge for solving problems of climate control. One may not take a crop indoors, it is true, but there is no valid reason, in the light of what has been already accomplished, why at critical periods which may be anticipated, the needed volume of surface air may not be sufficiently warmed; and the losses which have heretofore been considered inevitable be prevented.