The Independent.
The Independent.
The hybrid Polyantha Rose Psyche is a seedling from the dwarf Polyantha Rose Golden Fairy, crossed with the pollen of the Crimson Rambler. Its growth and habit, though more delicate, much resembles the Rambler. It is apparently quite hardy, and is very free flowering, but we fear not perpetual. The flowers are produced in clusters of from fifteen to twenty-five, and are 2 to 2½ inches across when fully expanded. In the bud stage they are very pretty and well formed. The color is white, suffused with salmon-rose and pink, with a yellow base to the petals. It is a real companion to Crimson Rambler.—The Gardeners' Chronicle.
ROSE HYBRID POLYANTHA "PSYCHE"--COLOR, PALE PINK.ROSE HYBRID POLYANTHA "PSYCHE"—COLOR, PALE PINK.
The theory of the origin of sleep which has gained the widest credence is the one that attributes it to anæmia of the brain. It has been shown by Mosso, and many others, that in men with defects of the cranial wall the volume of the brain decreases during sleep. At the same time, the volume of any limb increases as the peripheral parts of the body become turgid with blood. In dogs, the brain has been exposed, and the cortex of that organ has been observed to become anæmic during sleep. It is a matter of ordinary observation that in infants, during sleep, the volume of the brain becomes less, since the fontanelle is found to sink in. It has been supposed, but without sufficient evidence to justify the supposition, that this anæmia of the brain is the cause and not the sequence of sleep. The idea behind this supposition has been that, as the day draws to an end, the circulatory mechanism becomes fatigued, the vasomotor center exhausted, the tone of the blood vessels deficient, and the energy of the heart diminished, and the circulation to the cerebral arteries lessened. By means of a simple and accurate instrument (the Hill-Barnard sphygmometer), with which the pressure in the arteries of man can be easily reckoned, it has been recently determined that the arterial pressure falls just as greatly during bodily rest as during sleep. The ordinary pressure of the blood in the arteries of young and healthy men averages 110-120 mm. of mercury. In sleep, the pressure may sink to 95-100 mm.; but if the pressure be taken of the same subject lying in bed, and quietly engaged on mental work, it will be found to be no higher. By mental strain or muscular effort, the pressure is, however, immediately raised, and may then reach 130-140 mm. of mercury. It can be seen from considering these facts that the fall of pressure is concomitant with rest, rather than with sleep. As, moreover, it has been determined on strong evidence that the cerebral vessels are not supplied with vasomotor nerves, and that the cerebral circulation passively follows every change in the arterial pressure, it becomes evident that sleep cannot be occasioned by any active change in the cerebral vessels. This conclusion is borne out by the fact that to produce in the dog a condition of coma like to sleep, it is necessary to reduce, by a very great amount, the cerebral circulation. Thus, both carotids and both vertebral arteries, can be frequently tied at one and the same time without either producing coma or any very marked symptoms. The circulation is, in such a case, maintained through other channels, such as branches from the superior intercostal arteries which enter the anterior spinal artery. While total anæmia of the brain instantaneously abolishes consciousness, partial anæmia is found to raise the excitability of the cortex cerebri. By estimation of the exchange of gases in the blood which enters and leaves the brain, it has been shown that the consumption of oxygen and the production of carbonic acid in that organ is not large. Further, itmay be noted that the condition of anæsthesia is not in all cases associated with cerebral anæmia. Thus, while during chloroform anæsthesia the arterial pressure markedly falls, such is not the case during anæsthesia produced by ether or a mixture of nitrous oxide and oxygen.
The arterial pressure of man is not lowered by the ordinary fatigue of daily life. It is only in extreme states of exhaustion that the pressure may be found decreased when the subject is in the standing position. The fall of pressure which does occur during rest or sleep is mainly occasioned by the diminished rate of the heart. The increase in the volume of the limbs is to be ascribed to the cessation of muscular movement and to the diminution in the amplitude of respiration. The duty of the heart is to deliver the blood to the capillaries. From the veins the blood is, for the most part, returned to the heart by the compressive action of the muscles, the constant change of posture and by the respiration acting both as a force and suction pump. All of these factors are at their maximum during bodily activity and at their minimum during rest. On exciting a sleeper by calling his name, or in any way disturbing him, the limbs, it has been recorded, decrease in volume while the brain expands. This is so because the respiration changes in depth, the heart quickens, the muscles alter in tone, as the subject stirs in his sleep in reflex response to external stimuli. Considering all these facts, we must regard the fall of arterial pressure, the depression of the fontanelle, and the turgescence of the vessels of the limbs as phenomena concomitant with bodily rest and warmth, and we have no more right to assign the causation of sleep to cerebral anæmia than to any other alteration in the functions of the body, such as occur during sleep.
We may well here summarize these other changes in function:
(1) The respiratory movement becomes shallow and thoracic in type.
(2) The volume of the air inspired per minute is lessened by one-half to two-thirds.
(3) The output of carbonic acid is diminished by the same amount.
(4) The bodily temperature falls.
(5) The acidity of the cortex of the brain disappears.
(6) Reflex action persists; the knee jerk is diminished, pointing to relaxation in tone of the muscles; consciousness is suspended.
Analyzing more closely the conditions of the central nervous system, it becomes evident that, in sleep, consciousness alone is in abeyance. The nerves and the special senses continue to transmit impulses and to produce reflex movements. If a blanket, sufficiently heavy to impede respiration, be placed upon the face of a sleeping person, we know that it will be immediately pushed away. More than this, complicated movements can be carried out; the postilion can sleep on horseback; the punkah-wallah may work his punkah and at the same time enjoy a slumber; a weary mother may sleep, and yet automatically rock her infant's cradle. Turning to the histories of sleep walkers, we find it recorded that, during sleep, they perform such feats as climbing slanting roofs or walking across dangerous narrow ledges and bridges. The writer knew of the case of a lad who, when locked in his room at night to prevent his wandering in his sleep, climbed a partition eight to ten feet in height which separated his sleeping compartment from the next, and this without waking.
The brain can carry out not only such complicated acts as these, but it has been found to maintain during sleep its normal inhibitory control over the lower reflex centers in the spinal cord.
Thus, in sleeping dogs, after the spinal cord has been divided in the dorsal region, reflexes can be more easily evoked from the lumbar than from the cervical cord, because the former is freed from the inhibitory control of the brain.
The strength of stimulus necessary to pass the threshold of consciousness and to produce an awakening has been measured in various ways. It has been determined that it takes a louder and louder sound or a stronger and stronger electric shock to arouse a sleeper during the first two or three hours of slumber; after that period, the sleep becomes lighter and the required stimulus need be much less.
The alternative theories which have been suggested to account for the onset of sleep may be classed as chemical and histological.
In relation to the first, it has been suggested that if consciousness be regarded as dependent upon a certain rate of atomic vibration, it is possible that this rate depends on a store of intramolecular oxygen, which, owing to fatigue, may become exhausted; or it may be supposed that alkaloidal substances may collect as fatigue products within the brain, and choke the activity of that organ. Against this theory may be submitted the facts that monotony of stimulus will produce sleep in an unfatigued person, that over-fatigue, either mental or bodily, will hinder the onset of sleep, that the cessation of external stimuli by itself produces sleep. As an example of this last, may be quoted the case recorded by Strumpel of a patient who was completely anæsthetic save for one eye and one ear, and who fell asleep when these were closed. Moreover, many men possess the power, by an effort of will, of withdrawing from objective or subjective stimuli, and of thus inducing sleep.
The histological theories of sleep are founded on recent extraordinary advances in the knowledge of the minute anatomy of the central nervous system, a knowledge founded on the Golgi and methylene blue methods of staining. It is held possible that the dendrites or branching processes of nerve cells are contractile, and that they, by pulling themselves apart, break the association pathways which are formed by the interlacing or synapses of the dendrites in the brain. Ramon y Cajal, on the other hand, believes that the neuroglia cells are contractile, and may expand so as to interpose their branches as insulating material between the synapses formed by the dendrites of the nerve cells. The difficulty of accepting these theories is that nobody can locate consciousness to any particular group of nerve cells. Moreover, the anatomical evidence of such changes taking place is at present of the flimsiest character.
If these theories be true, what, it may be asked, is the agency that causes the dendrites to contract or the neuroglia cells to expand? Is there really a soul sitting aloof in the pineal gland, as Descartes held? When a man like Lord Brougham can at any moment shut himself away from the outer world and fall asleep, does his soul break the dendritic contacts between cell and cell; and when he awakes, does it make contacts and switch the impulses evoked by sense stimuli on to one or other tract of the axons, or axis cylinder processes, which form the association pathways? Such a hypothesis is no explanation; it simply puts back the whole question a step further, and leaves it wrapped in mystery. It cannot be fatigue that produces the hypothetical interruptions of the dendritic synapses and then induces sleep, for sleep can follow after fatigue of a very limited kind. A man may sleep equally well after a day spent in scientific research as after one spent in mountain climbing, or after another passed in idling by the seashore. He may spend a whole day engaged in mathematical calculation or in painting a landscape. He fatigues—if we admit the localization of function to definite parts of the brain—but one set of association tracts, but one group of cells, and yet, when he falls asleep, consciousness is not partially, but totally suspended.
We must admit that the withdrawal of stimuli, or their monotonous repetition, are factors which do undoubtedly stand out as primary causes of sleep. We may suppose, if we like, that consciousness depends upon a certain rate of vibration which takes place in the brain structure. This vibration is maintained by the stimuli of the present, which awaken memories of former stimuli, and are themselves at the same time modified by these. By each impulse streaming into the brain from the sense organs, we can imagine the structure of the cerebral cortex to be more or less permanently altered. The impulses of the present, as they sweep through the association pathways, arouse memories of the past; but in what way this is brought about is outside the range of explanation. Perhaps an impulse vibrating at a certain rate may arouse cells or fibrils tuned by past stimuli to respond to this particular rate of vibration. Thus may be evoked a chain of memories, while by an impulse of a different rate quite another set of memories may be started. Tracts of association are probably formed in definite lines through the nervous system, as during the life of a child repeated waves of sense impulses beat against and overcome resistances, and make smooth pathways here and there through the brain structure. Thus may be produced growth of axons in certain directions, and synapses of this cell with that. If the same stimulus be often repeated, the synapses between groups of cells may become permanent. A memory, a definite line of action which is manifested by a certain muscular response, may thus become structurally fixed. If the stimulus be not repeated, the synapses may be but temporary, and the memory fade as the group of cells is occupied by a new memory of some more potent sense stimulus. Many association tracts and synapses are laid down in the central nervous system when the child is born. These are the fruits of inheritance, and by their means, we may suppose, instinctive reflex actions are carried out.
So long as the present stimuli are controlled by past memories and are active in recalling them, so long does consciousness exist, and the higher will be the consciousness, the greater the number and the more intense the character of the memories aroused. We may suppose that when all external stimuli are withdrawn, or the brain soothed by monotony of gentle repetition, and when the body is placed at rest, and the viscera are normal and give rise to no disturbing sensations, consciousness is then suspended, and natural sleep ensues. Either local fatigue of the muscles, or of the heart, or ennui, or exhaustion of some brain center usually leads us to seek those conditions in which sleep comes. The whole organism may sleep for the sake of the part. To avoid sleeplessness, we seek monotony of stimulus, either objective or subjective. In the latter case, we dwell on some monotonous memory picture, such as sheep passing one by one through a gap in the hedge. To obtain our object, we dismiss painful or exciting thoughts, keep the viscera in health, so that they may not force themselves upon our attention, and render the sense organs quiet by seeking darkness, silence and warmth.—L.H., in Nature.
At the time that we described the Demeny chronophotographic apparatus we remarked that it had the advantage of permitting of the projection of very luminous images of large dimensions; but it is certain that the cases are somewhat limited in which there is any need of using a screen 24 or 25 feet square, and, as a general thing, one 6 or 10 feet square suffices. The manufacturer of the apparatus, M. Gaumont, has, therefore, been led to construct a small size in which the bands have the dimensions usually employed in the French and other apparatus, thus permitting of the use of such as are now found in abundance in the market.
By reducing the size, it has been possible further to simplify the construction, and at the same time to reduce the price, thus making of the new form a genuine amateur apparatus.
It will be remembered that the Demeny principle consists especially in the avoiding of traction upon the perforated part of the band, which is the portion that always presents the most fragility. This principle has naturally been preserved in the small model, and a preservation of the bands for a long time is thus assured.
Fig. 1--ARRANGEMENT OF THE SENSITIZED BAND IN TWO MAGAZINES.Fig.1—ARRANGEMENT OF THE SENSITIZED BAND IN TWO MAGAZINES.
Fig. 2--ARRANGEMENT FOR TAKING VIEWS WITH SPECIAL GEARING FOR THE WINDING OF THE BAND.Fig.2—ARRANGEMENT FOR TAKING VIEWS WITH SPECIAL GEARING FOR THE WINDING OF THE BAND.
The apparatus is reversible, and may be used for making negatives as well as for projecting positives. In its new form it is easily transportable and is no more bulky than an ordinary 5 by 7 inch apparatus. Nothing is simpler then than to carry it on a journey, if one desires to make his own negative bands. Since the sensitized film has to be protected against the light during its entire travel, two magazines have been arranged (Fig. 1). One of these, A, which is fixed upon the top of the camera, contains the clean film, while the other, B, which is placed beneath the objective, receives the strip after it has been acted upon by the light. A train of toothed wheels, C (Fig. 2), actuates the roller of this second magazine. This arrangement may, moreover, be utilized also when projections are made, if one does not desire the band to float in measure as it unwinds behind the objective. As the upper magazine is entirely closed when it is placed upon the apparatus, it is necessary, in order to prepare for taking a negative, to pull out a few inches of the film, pass the latter over the guide roller and fix the extremity to the winding roller in the lower magazine.
It is clear that we can have any number of magazines whatever for carrying about, all charged, just as one carries the frames of his ordinary camera.
Chronophotography presents no more difficulty than ordinary photography as regards the taking of negatives, and the amateur who has not the proper facilities for developing and printing the latter can have these operations performed by a professional. Animate projections are beginning to be introduced into parlors, and some day will entirely replace the magic lantern therein. The excitement caused by the catastrophe at the Charity Bazar is now calmed, and it has been ascertained that the accident was not due to the lamp of the projector, but to a carelessly handled can of ether. So the extension of this sort of spectacle, momentarily arrested, is taking a new impetus, which will be further aided by the apparatus under consideration, for the description of which and the illustrations we are indebted to La Nature.
The complaint of high prices of India rubber is as old as the rubber industry, one result of which has been an unceasing effort to discover a practical substitute. Never was the secret of the transmutation of metals sought more persistently by ancient philosophers than the secret of an artificial rubber has been by modern chemists, but, thus far, the one search has been hardly more successful than the other. One discovery has been made, however, by which our rubber supplies have been so far conserved that, for the want of it, we might be obliged now to pay double the current prices for new rubber. This is the reclaiming of rubber from worn-out goods, in a condition fit for use againin almost every class of products of the rubber factory.
Soon after the vulcanization of rubber became fully established, attempts began to be made to "devulcanize" the scrap and cuttings of rubber which accumulated in the factories. So extensive were these accumulations that one company are reported to have built a road with rubber scrap through a swamp adjacent to their factory, while most other manufacturers were unable to find even so profitable a use for their wastes. As time advanced there came to be large stocks, also, of worn-out rubber goods, such as car springs and the like, all of which appealed to a practical mind here and there as being of possible value, since the price of new rubber kept climbing up all the while.
No fewer than nineteen patents were granted in the United States for "improvements in devulcanizing India rubber," or "restoring waste vulcanized rubber," beginning in 1855, or eleven years after the date of Goodyear's patent for the vulcanization process. In that year Francis Baschnagel obtained a patent for restoring vulcanized rubber to a soft, plastic, workable state, by treating it with alcohol absolutus and carbon bisulphuratum, in a closed vessel, without the application of heat. Later he obtained a patent for accomplishing the same result by "boiling waste rubber in water, after it has been reduced to a finely divided state;" and still later, one for treating the waste to the direct action of steam.
Patents were granted in 1858 to Hiram L. Hall, for the treatment of waste rubber by boiling in water; also, by subjecting it to steam; and again, by combining various resinous and other substances with it. The two inventors named assigned their patents to the Beverly Rubber Company, of Beverly, Mass., controlled then by the proprietors of the New York Belting and Packing Company, and their processes became the basis of an important business in rubber clothing.
The low cost of the devulcanized rubber, as compared with new rubber, alone gave them a great advantage over other manufacturers, in addition to which they escaped the payment of a license to work under the Goodyear patents.
Many army blankets, made for the government during the civil war, were waterproofed with Hall's devulcanized rubber, and from that period little new rubber has been used in the manufacture of heavy rubber coats. The other patents in this class do not deserve special mention.
It having been established that rubber is rubber, no matter where found, manufacturers gradually turned their attention beyond the scraps and cuttings which remained after making up their goods. There was beginning to be a good demand for ground-up rubber car springs, wringer rolls, tubing and other rubber goods free from fiber, after it had been so treated as to remove the sulphur contents and restore the gum to a workable condition. But this left out of account rubber footwear, belting, and hose, not to mention the later heavy production of bicycle tires. There were only a few uses to which rubber waste containing fibrous material could be put when ground up and devulcanized without the removal of the fiber. It could be put into a cheap grade of steam packing or mixed in a powdered form with new rubber for the heels of rubber boots and shoes. There was an early patent for a process for "combining fibrous materials with waste vulcanized rubber, rendered soft and plastic." But all the other patents which come within the scope of this article had for their object the separation of fibers from the rubber.
An important advance was marked by the Hayward patent (No. 40,407), granted in 1868, for "boiling waste rags of fibrous material and rubber in an acid or alkali, for the purpose of destroying the tenacity of the fibers of the rags, so that the rubber may be reground." But this process extended only to the weakening of the fibers, and not their complete destruction. A later patent, in the same year, provided for exposing the ground rubber waste to the direct action of flames of gas or inflammable liquids, by which the foreign matters would be consumed and the rubber rendered plastic and cohesive, but it is not on record that this process received any particular application.
The principal activity of invention in the field of reclaiming rubber dates from 1870, since which year 37 patents have been granted for processes more or less distinctive from those which had for their object only the devulcanization of rubber. Prior to that time the use of rubber reclaimed from fibrous wastes had been confined practically to one large factory in Boston and one near New York. One concern, for a while, bought old rubber shoes and sent them to women in the country, whom they paid so much a pound for the rubber stripped off—a very expensive process. There were several claimants for priority in the matter of reclaiming rubber by the processes which finally became standard, and some conflicting interests were brought together under the head of the Chemical Rubber Company. This corporation controlled the leading patents for the "acid" process, licensing various parties to work under them, and bringing suits against concerns who reclaimed rubber without their license. In 1895 the United States courts decided in favor of the defendants, practically rendering the patents invalid, on the ground that the inventions claimed under them had been disclosed by the Hall patents of 1858 and the Hayward patent of 1863.
The two patents upon which the suits for infringement rested principally were No. 249,970, granted to N.C. Mitchell, in 1881, and No. 300,720, granted to the same, in 1884. About the same time the Rubber Reclaiming Company, formed in 1890 by the combination of five leading rubber reclaiming plants, and working under license from the company above named, was resolved into the original elements. There were about that time five other rubber reclaiming plants in the United States, operating either the "acid" or the "mechanical" process, besides nine general rubber factories producing their own reclaimed rubber by the "acid" process. While several of the latter—rubber shoe concerns controlled by the United States Rubber Company—have been consolidated, there has been an increase in the number of rubber manufacturers reclaiming their own rubber, since the end of the patent litigation, so that the total number of reclaiming plants now probably is twenty.
The first step in any process for reclaiming rubber is the grinding of the waste, for which purpose several machines have been designed specially, an early patent for disintegrating rubber scrap by "subjecting it to the abrading action of grindstones" having failed to meet with favor. The most usual chemical treatment is a bath in a solution of sulphuric acid in lead-lined tanks. Generally heat is employed to hasten the process, through the medium of steam, in which case the tanks are tightly closed. The next step is the washing of the scrap, to free it of acid and dirt, after which it is sheeted by being run between iron rollers and hung in drying rooms. As soon as it has become dry it is ready for sale.
In the extended litigation over the acid process patents, the points at issue related to the strength of the acid named in the various specifications and also to the methods of applying steam. Prof. Charles F. Chandler, called as an expert in one case, testified that the effects of acids, such as sulphuric or hydrochloric, upon rubber and rubber compounds, under varying strength and temperature, had been known at a period antedating all the patents then the basis of suits for infringement; also that their effect upon cotton and woolen fabrics had been equally well known. They had the same effect upon fibers, whether the latter were combined with rubber or not, but very strong acids would affect the rubber injuriously. The line of defense in this case was that "no invention was required in selecting the strength of acid; only the common sense of the manufacturer, aided by his skill and experience, was necessary to bring about the proper results." In support of this a factory superintendent testified that varied stocks required skill and judgment in their treatment and more or less variation as to the strength of acid, temperature, etc.
As to the use of steam, Prof. Henry B. Cornwall, of Princeton College, called as an expert in another case, testified that, having put to a test the specifications in all the patents involved, he had found it necessary in no case to inject live steam into the mixtures of acid and rubber scrap in order to effect the decomposition and removal of either woolen or cotton fiber. The use of the acids specified was sufficient for this, and the various high temperatures called for were not essential for the destruction of the fibers. He neglected to mention, however, that the steam served an equally important purpose in devulcanizing the rubber.
It appeared that the practice in different factories had included the use of sulphuric acid varying from a 2½ per cent. solution to the full commercial strength of the acid, but one of the defendant companies based their case upon their use of acid of the strength of 28° to 30° Baumé, whereas the patent they were charged with infringing specified a strength of 66°. Their tanks were lead-lined and provided on the interior with steam pipes running down the sides and along the bottom, the sections at the bottom being perforated and the steam admitted at a pressure of 75 to 80 pounds. The chemical treatment lasted from 2½ to 4 hours.
The sulphuric acid treatment, however, is confined mainly to scrap containing cotton fiber. Where woolen fibers occur, which is much less frequently, their disintegration is accomplished generally by the use of caustic soda.
In the mechanical process of reclaiming rubber, the rubber is separated from the fiber, after the whole has been finely ground, by means of an air blast, the method being not unlike that practiced by furriers for separating hair and fur from bits of pelt after skins have been finely divided. As the powdered waste comes from the blower, the rubber falls in a heap near the machine, while the particles of fiber, being lighter, are carried far enough away to make the separation complete. Devulcanization in this case is effected by exposure to live steam at a high temperature. No oil is used in the process, the sheeting of the product being facilitated by means of hot friction rollers.
The cost of reclaiming rubber by the acid process is less than by mechanical means, for which reason the former is now much more generally used. But some manufacturers are willing to pay more per pound for mechanically-reclaimed rubber, either (1) because it can be "compounded" more heavily than the acid product, or (2) because of certain inherent disadvantages of the latter. It is the testimony of these manufacturers that the action of sulphuric acid upon whiting (one of the most common adulterants used in rubber shoes) is to turn it into sulphate of lime—an ingredient which is far from advantageous in a rubber compound. Again, any acid which may remain in the reclaimed rubber is liable to rot thin textile fabrics with which it may be combined in manufacture. Finally, rubber recovered by the chemical process, it is claimed, is harder than that obtained by any other; so that it is usual to add, during vulcanization, in order to soften the product, the residuum obtained from petroleum manufactures, or palm or other oils. Unvulcanized rubber clippings also have been used for this purpose. One of the most successful of our rubber factory superintendents, who formerly made the reclaimed rubber used by his factory, has stated that his practice was to subject the material to an alkaline bath after the acid treatment, not only for the better cleaning of the rubber, but to neutralize any acid which might remain. Considering all the points involved, it was his opinion that, when scrap rubber is cheap, the mechanical process is the more economical, while, if it is high priced, the acid process has the advantage. Since this expression of opinion, however, prices of rubber scrap have ranged constantly at higher figures than before, and there is no indication that we shall have again what was known formerly as "cheap" scrap. It is not surprising, therefore, that the volume of mechanical "shoddy" should be placed by the best estimates at not above one-sixth of the total production of reclaimed rubber in the United States. And the acid product, with all its admitted shortcomings, is still superior to any of the so-called rubber substitutes.
Reclaimed rubber is not to be considered as an adulterant, except in the same sense as fillings, like whiting, litharge or barytes, the use of which in rubber compounds often gives to the product desirable qualities that are unobtainable by the use of "pure gum." It lacks some of the qualities of good native rubber, and yet it is rubber, and fills its proper place as acceptably as any raw material of manufacture. Rubber shoes made of new gum entirely would be too elastic, and for that reason would draw the feet, besides being too costly for the ordinary trade. The construction of a rubber shoe, by the way, is well adapted for the use of different compounds for the different parts. Rubber enters into twenty-six pieces of a rubber boot and nine or more pieces of a rubber shoe. Consequently, as many different compounds may be used, if desired, for the output of a single factory for rubber footwear. The highest grades of native rubber may be used for waterproofing the uppers of a fine overshoe, while reclaimed rubber, of a cheap class even, may be good enough for the heel, which requires only to be waterproof and durable, without too much weight, and with no elasticity. Reclaimed rubber goes into many classes of goods of high grade. The result is that such goods have been cheapened legitimately, placing them within the reach of immense numbers of consumers who otherwise would be obliged to do without.
While the extensive use of reclaimed rubber is a matter of common knowledge to all who are familiar with the rubber industry, there are nowhere available any statistics of either the absolute or comparative volume of its consumption, with the single exception of the official returns of imports into Canada. There separate accounts are kept of crude India rubber and of recovered rubber received in each year, and as only a consuming market exists for these commodities in the Dominion, the figures given below may be taken to represent closely the actual consumption by the rubber factories of Ontario and Quebec. It is interesting to note the heavy growth of the percentage of recovered rubber shown in the table, all the figures representing pounds:
If it were possible to examine the books of the several rubber reclaiming plants on this side of the border, including rubber shoe and mechanical goods factories producing their own reclaimed rubber, the percentage of this material used, in comparison with the total rubber consumption, might be found to be as great in the United States as in Canada. The rubber manufacture in the Dominion, in its inception, was practically an offshoot from the industry in this country. Our manufacturers supplied the Canadian demand for rubber goods until, under the stimulus of heavy protective duties, rubber works were established beyond the border, since which time, to quote a leader in the trade in the United States, "the methods of the Dominion rubber industry have mirrored the best practice in our country." Hence it seems not unreasonable to conclude that if the Canadians are using so large a percentage of reclaimed rubber, they are doing no more nor less than the older and larger concerns here. The most trustworthy authorities place the consumption of new rubber in the United States during 1897 at not far from 35,000,000 pounds. Assuming that the rate of consumption of reclaimed rubber was as great as in Canada, we have 18,435,000 pounds more, or a total of 53,433,000 pounds. But there are producers of reclaimed rubber who insist that the amount of this material used in this country equals, pound for pound, the consumption of new rubber.
The use of reclaimed rubber in Europe is increasing gradually, and especially in Great Britain. The American product is sold extensively in that country, and some native reclaiming plants have been started. The most extensive "galosh" factory in Russia, which is said to be the largest in the world, is reclaiming rubber according to American methods. But, as a rule, the Continental rubber manufacturers make more use of "substitutes," a class of materials which has not found favor in America. These rubber substitutes belong chiefly to the class of oxidized oils and may be classed in three divisions: Those obtained (1) by the action of oxygen or air on linseed oil; (2) by acting on rape oil with chloride of sulphur; and (3) by the action of sulphur on rape oil at a high temperature. The first class has little application to the rubber trade, though its use is universal in the linoleum industry. In Europe the chemist holds a more important position in the rubber manufacture than here, one result of which has been cheaper compounds of rubber and another the satisfactory employment of the refractory African rubbers long before they were used extensively in the United States. Hence the cost of raw materials in the rubber industry has been, on the whole, cheaper abroad. The Europeans have had an advantage, too, in respect to cheaper labor, which has offset somewhat our own advantage from the use of reclaimed rubber as a cheap material.
There are numerous grades of reclaimed rubber, due to differences in the quality of stock used, and also to the different degrees of care used in its preparation, according to the requirements of manufacturers. The declared value of reclaimed rubber exported from New York during July, 1897, averaged 12.6 cents per pound, while the value of exports for September averaged only 9.1 cents. The average value for the eight months ending February 28, 1898, was 10.08 cents per pound. The total declared value of such exports for the fiscal year 1896-97 was $119,440, which, at the prices prevailing since, would represent considerably more than 1,000,000 pounds. Some of the material sold at home is known to bring less than any prices quoted above. "Mechanical" stock brings about two cents per pound more than "acid" stock of corresponding grade.
The collection of old rubber has acquired large proportions as an adjunct to the trade in junk or rags. Not long ago the estimated yearly collection of rubber shoes alone amounted to 18,000 tons, and since that time the business in bicycle tire scrap has also become very large. During the past ten years the price of old rubber shoes has ranged between $60 and $120 per ton in carload lots, being at present about $90 per ton. Some 1,500 tons of rubber scrap are imported annually by the reclaiming companies in the United States.
In the Baltic Sea there are more wrecks than in any other place in the world. The average throughout the year is one each day.
The Austriangovernment has ordered thirty-seven engines arranged to burn kerosene, for use in the Arlberg tunnel, in which lack of proper ventilation at present causes the tunnel to remain filled with smoke.—Uhland's Wochenschrift.
One of the first essentials to modern military enterprise is the establishment of a military railway system for war purposes. To be in a position to carry out efficiently and speedily what we may expect to be called upon to do on the outbreak of serious war, previous preparation in time of peace is an absolute requisite. In connection with General Sherman's operations in Georgia, during the American civil war, an army was supplied for six and a half months over a line 473 miles long. The corps of workmen was 10,000 strong, and on one occasion replaced 35,000 sleepers and nine miles of rails in seven days. The true defense of the line was effected by the engineers always having men and material ready. In spite of the large and skilled railway population on which the army could call, and of the fact that practically the nation was in arms, it was found extremely difficult to keep this railway construction corps together until they were placed under a severe military discipline.—United Service Gazette.
A hospitalcar has been introduced on the Belgian railroads, says The Engineer. It is designed for use in the event of a serious railway accident, and can be run to the spot where the wounded may be picked up and carried to the nearest city for treatment, instead of being left to pass hours in some wayside station while awaiting surgical attendance. The interior of this car is divided into a main compartment, a corridor on one side and two small rooms at the end. The largest compartment, the hospital proper, contains twenty-four isolated beds on steel tubes hung upon powerful springs; each bed is provided with a small movable table, a cord serving to hold all the various small objects which may be needed, and each patient lies in front of two little windows, which may be closed or opened at will. The corridor on the outside of the hospital chamber leads to the linen closet and the doctor's apartment; in the latter is a large cupboard, the upper portion being used for drugs, while the lower is divided into two sections, one serving as a case for surgical instruments and the other as a receptacle for the doctor's folding bed.
The dustcollected from the smoke of some Liege furnaces, burning coal raised from the neighboring mines, produces, when dissolved in hydrochloric acid, a solution from which considerable quantities of arsenic and several other metallic salts may be precipitated. Commenting on this fact, ascertained by M.A. Jorissen, M. Francis Maur asks whether this breathing of arsenic and other minerals in a finely divided state may not account for the singular immunity from epidemics enjoyed by certain industrial districts, such as that of Saint Etienne, and hopes that some mine doctor will throw additional light on the subject. In the meanwhile, it may be suggested that the ventilating effect of the numerous chimneys in iron making and other industrial centers has its due share in constantly driving off the vitiated air and replacing it by fresh quantities of pure air. At any rate, when pestilence was raging in the high and pleasant quarter of Clifton, its inhabitants migrated to the low-lying and not overclean parish of St. Philips, Bristol, where the air is black from the smoke of numerous chimneys, but where also the mortality compared very favorably with that in the fashionable quarter.
A two-speedmovable sidewalk, of the Blot, Guyenet and De Mocomble type, is to be used for conveying visitors at the Paris Exposition, says Engineering News. It differs from those of Chicago and Berlin in the reduction of the weight of the moving platform by spacing the driving wheels 127.5 feet apart and using electricity as a motive power. The driving wheels are mounted in the bed of the track and impart motion to a central rail on the under side of the platform. Bearing wheels, spaced about 20 feet apart under this rail, also carry the platform, and the central rail supports one-half the total weight of the platform; small side wheels carry the other half on side tracks. This arrangement enables the platform, which is divided into sections and hinged, to pass around quite sharp curves. The high speed platform, 4 feet 3 inches wide, is supposed to move at the rate of 6½ miles per hour on a 35½-inch gage track; the slow platform is 31½ inches wide, moves at half speed and runs on a 17¾-inch gage track. The whole structure will be elevated on girders carried by cast iron columns, with stations about 656 feet apart. The high speed platform weighs 146 pounds per lineal foot; and with passengers, nearly 400 pounds per foot. The slow speed platform weighs about half this. The track will be about 2½ miles long; the initial motive power is figured at 472 H. P. and the carrying capacity at 38,880 per hour.
The "schlamm,"or mud, thrown down from the water of coal washing has hitherto been regarded as worthless, says The Engineering and Mining Journal, except that sometimes a portion of the coal particles it contained have been separated and made of value by a washing process; but Bergassessor Haarmann, of Friedrichsthal, has invented a new method for treating it dry and dividing it into two products, one of which, with low ash content, is distinguished by its granular nature, while the other contains a large proportion of ash and is of the fineness of flour. The former of these two products is, on account of its low ash content, useful for various purposes, and the latter constitutes a fuel quite ready for use in coal dust firing. The method is founded on the circumstances, hitherto lost sight of, that the incombustible constituents of the "schlamm" chiefly consist of clay which was formerly more or less dissolved in the wash water; and on the mud being dried and subjected to a suitable mechanical process, the clay falls into fine dust, while the coal particles, on the contrary, retain their granular nature. The method is carried out by drying the mud and a subsequent fine sifting, which effects a breaking up of the lumps that occur in the dried "schlamm," and a separation into the two products above named. The dust that falls through the sieve has a high ash content, being in the nature of flour, while what remains behind is granular and has a low ash content. It seems to us that this game is hardly worth the candle.
Electricity atthe Paris Exposition.—Electricity will play a large part at the Paris Exposition of 1900, says the Revue Technique. No less than 15,000 h.p. will be used for lighting and 5,000 h.p. for furnishing electric power to the various parts of the grounds. As far as possible all the machinery exhibited will be shown at work and for this purpose electric conductors will be laid down to all points on the grounds. The boiler plant will be located at the end of the Champ de Mars, and will occupy two spaces of 130 X 390 feet each, one being devoted to French boilers and the other to those of foreign makers. This plant will be in itself a very interesting exhibit. It is proposed to provide a capacity for evaporating not less than 440,000 pounds of water per hour.
An interestinglittle plant in which the rise and fall of the tides is used as motive power for the generation of electricity is described in L'Electricien. Near Ploumanach, on the northern coast of France, where the tides have a daily range of 39 feet, a small fish pond separated from the sea by a dike is arranged with gates so that at high tide the water flows in and fills it, the gates closing automatically when the tide recedes. The machinery of an old grist mill is used to operate a small dynamo, which charges a storage battery and furnishes light for the fish industry there. Another wheel in the same mill works an ice making machine, the whole being under the charge of one man. It is stated that the total daily expense for generating about 2,000 horse power hours is only $2.
Peat bogsas generators of electrical power are suggested by Dr. Frank in Stahl und Eisen. He says that the great peat bogs of North Germany may be thus utilized, and figures that one acre of bog, averaging 10 feet in thickness, contains about 1,000 tons of dried peat, or 313,000 tons per square mile; and 430 square miles would be equivalent in heating power to the 80,000,000 to 85,000,000 tons of coal annually mined in Germany. The bogs of the Ems Valley alone cover 13,000 square miles; and Dr. Frank proposes the erection in that district of a 10,000 horse power electric station, which would yearly consume 200,000 tons of peat, or the product of 200 acres. He would use the electrical energy on the Dortmund and Emshaven Canal, and for the manufacture of calcium carbide.
The successattending an application of electric towing on the Burgundy Canal was such that two new applications of electricity to canal haulage and also for barge propulsion were made last year in the neighborhood of Dijon, on the same canal, under the superintendence of M. Gaillot, Ingénieur des Ponts et Chaussées. In the method of haulage, says The London Engineer, the receptor dynamo is mounted on a tricycle, to which the name of "electric horse" has been given, and which, running on the towing path, takes its current from an air line consisting of two wires, mounted five meters (nearly 17 feet) above the surface. This "horse," which weighs two tons, and is guided by a driver mounted upon it through the front wheel, proceeds on the towing path like a traction engine; and the boats are connected with it by a rope, with automatic disengaging gear, in case the force of the stream or a gust of wind should drive a boat backward. Speeds of from 1,990 to 4,240 meters (mean 3,319 yards) were obtained with the electric horse, towing from three to four boats, so that it is more suitable than the electric propeller for towage in rivers or very long reaches; but it requires a driver, while the propeller, with which speeds of from 2,150 to 4,240 meters (mean 3,406 yards) per hour were obtained, is worked by the bargee on board his boat. The towing path is not worn, and there is no occasion for a tow rope, which always causes difficulty when two boats cross one another. M. Maillet and M. Dufourny, Belgian Ingénieurs des Ponts et Chaussées, who watched the trials, conclude that a practical solution of the question depends upon the cost of producing the motive power; but they also consider that horse haulage on canals will soon be superseded by mechanical traction, based on the use of an automotive tricycle, working with petroleum or some other hydrocarbon, and capable of running on the tow path without requiring any fixed plant.
It haslong been known that feathers and hair are electrical bodies, but until recently we have had little information about their electrical properties or the conditions in which these properties are manifested. Most of these phenomena were first observed by Exner, and in the work of Dr. Schwarze are found collected a mass of facts that cannot fail to interest the physician and the biologist; besides, we find there a description of Exner's apparatus which was used by Schwarze in most of his experiments on electrical phenomena of this kind. By the side of gold leaf electroscopes we see a feather electroscope, which is fastened to its support by means of a silken thread. A feather waved through the air is positively electrified, while the air itself seems to be charged with negative electricity.... Two feathers rubbed together in the natural position are so electrified that their lower surface is negative and the upper positive.... These experiments and others still have been utilized to study the vital relations of animals and the biological signification of these phenomena. Most feathers stick together and remain so even after being dried; if they then are waved through the air, the barbs of the feather separate, owing to differences of electrification. No bird needs to attend to its plumage at the end of a long flight, for while the large feathers are positively electrified by friction against the air, the white down has become negative, and so there is attraction between it and the feathers. Another consequence of this production of electricity during flight is that during winds, even the most violent, the plumage does not become ruffled, but rests tightly against the bird's body, for in this case the wing feathers, which overlap, rub against each other and become electrified in contrary senses. If the bird flies toward the ground, flapping its wings, it compresses the air below them, and, supposing that the wing feathers can bend aside, the experiments of Exner show that by the friction the upper side of one feather and the lower side of that which is just above are electrified oppositely, the more powerfully as the rubbing is greater, which always causes them to resume the normal position.—L'Electricien.
Removal of Ink from Hectograph.—It is recommended in Südd. Ap. Ztg. to pour crude hydrochloric acid upon the hectograph, rub with a wad of cotton, then wash off by holding under cold running water and drying with a cloth. The hectograph may be used again immediately.
To Clean Wall Paper.—Four ounces of pumice stone in fine powder are thoroughly mixed with 1 quart of flour and the mass is kneaded with water enough to form a thick dough. This dough is formed into rolls about 2 inches in diameter and 6 or 8 inches long; each one is sewed up in a piece of cotton cloth and then boiled in water for from 40 to 50 minutes—long enough to render the dough firm. After cooling and allowing the rolls to stand for several hours, the outer portion is peeled off and they are then ready for use, the paper being rubbed with them as in the bread process.—Druggist's Circular.
Insulating Compound.—Prof. Fessenden recommends for armature work a compound made by boiling pure linseed oil at about 200 degrees with ½ per cent. of borate of manganese, the boiling being continued for several hours, or until the oil begins to thicken. An advantage of this borated oil is that it always retains a slight stickiness, and so gives a good joint when wrapped around wires, etc. Many substances so used are not sticky and let moisture in through the joints. Where a smooth surface is required, it is readily obtained by dusting on a little talc. It can also be given a coat of japan on the outside.—American Electrician.
How to Clean Diatoms.—As a general rule, we may say that every specimen of diatomaceous earth or rock needs a special treatment. The following, however, may serve as a basic treatment, from which such departure may be taken in each case as the nature of the specimen would indicate: Boil the material in hydrochloric acid, in a test tube, from two to five minutes. Let settle, pour off the hydrochloric acid, substitute nitric acid in its place, and boil again for two or three minutes. Pour into a beaker of water, stir a moment with a glass rod and let settle. After the material has fallen to the bottom, decant the liquid, and fill with fresh water. Repeat the operation until the water no longer shows an acid reaction. A portion of the deposit may now be examined, and if not clean, boil the deposit with tincture of soap and water in equal parts, decant, wash, first with water, then with stronger ammonia water, and finally, with distilled water. This usually leaves the frustules bright and sharp.—National Druggist.
Red Indelible Ink.—It is said that by proceeding according to the following formula, an intense purple red color may be produced on fabrics, which is indelible in the customary sense of the word.
Moisten the place to be written upon with No. 1 and rub a warm iron over it until dry; then write with No. 2, and, when dry, moisten with No. 3. An intense and beautiful purple-red color is produced in this way. The following simpler and less expensive method of obtaining an indelible red mark on linen has been proposed by Wegler: Dilute egg albumen with an equal weight of water, rapidly stir with a glass rod until it foams, and then filter through linen. Mix the filtrate with a sufficient quantity of finely levigated vermilion until a rather thick liquid is obtained. Write with a quill, or gold pen, and then touch the reverse side of the fabric with a hot iron, coagulating the albumen. It is claimed that marks so made are affected by neither soaps, acids nor alkalies. This ink, or rather paint, is said to keep moderately well in securely stoppered bottles, but we should not rely on it as a "stock" article. A white paint for marking dark colored articles might be made by substituting zinc white for the red pigment in the foregoing formula.—Druggist's Circular.
Brown or Black Discoloration of Silvered Mirrors.—Generally these spots are due to faulty manipulation, too great dilution of the silver solution, or touching the plates with the fingers after they have been cleaned. Sometimes, however, they are due to chemical defects in the glass itself. In these cases, as a general thing, the discolorations occur only after several days—a faultless mirror having been made at first, and the browning subsequently developing slowly. The writer was a student in the laboratory of Baron Liebig during the time that distinguished chemist was carrying out the series of experiments which resulted in devising a method of making silver mirrors commercially. One of the greatest troubles with which he had to contend was this browning—the cause for which was never fully cleared up by him. Some years ago, the writer, having in his possession two mirrors made by Liebig, and which had gradually become brown throughout, undertook an examination of the deposit (which had been thoroughly protected from extraneous influences by a strong film of varnish), and was surprised to find that it consisted of a layer of silver sulphide. Without going into detail, the source of the change was later found to lie within the glass itself. In making glass to be used for mirrors, a considerable portion of sodium sulphate is used, and in annealing, this is partly reduced to sodium sulphide, which effloresces on the surface of the glass. This efflorescence is, of course, removed on cleaning the glass before silvering; but it is found that, in many instances, on exposure of the mirror to the light for some time, a further efflorescence occurs, and it is this which produces the discoloration in cases such as we have cited. It has been suggested that the tendency to subsequent efflorescence may be corrected by boiling the plates, intended for silvering, for a couple of minutes, in a 10 per cent. solution of sodium carbonate or bicarbonate. We have no experience with the process, however.—National Druggist.
As a rule, domestic animals are accorded very little space in zoological gardens, but, although it is doubtless the first duty of these popular institutions to show visitors animals which live in a wild state in foreign lands, it is well, where there is sufficient space and adequate means, to extend the limits of the collection so as to include natives of our own woods and fields, thus enabling people of a great city who are unfamiliar with nature to form an idea of the changes wrought in animal life by the influence of man, for domestic animals are a great aid in the study of natural history. The accompanying engravings are reproductions of instantaneous photographs of occupants of the new sheep and goat house—mostly foreign breeds; but there are a few that belong to that South European-Asiatic group which are looked upon as the progenitors of the domestic sheep: the mouflon, of Sardinia and Corsica (Ovis Musimon L.), which has a coat of brownish red, flecked with darker color; and the slender, long-legged, reddish-gray sheep of Belochistan (Ovis Blanfordi Hume). The first glance at these creatures convinces one that they are wild, not domestic sheep, an impression which is caused chiefly by the monotonous coloring and the dry, short coat, which bears no resemblance to the thick fleece of the tame sheep, although the eye is soon attracted by other differences, such as the shape of the tail, which is short and thick, and of the horns, which extend over the back and then turn inward, so that when the old ram is kept in captivity, it is necessary to cut off the points of the horns to prevent their boring into the flesh of its neck. Horns of this shape form a strong contrast to those with snail-like windings and points standing away from the body. When looking at one of these sheep from the front, it will be noticed that the left horn turns to the right and the right horn to the left.