But besides theseAcarinediseases, there seems to be one (unless with Linné we regard the plague as of this class[134]) more fearful and fatal than them all. You will, perhaps, conjecture I am speaking of that described by Aristotle and Sir E. Wilmot as the Phthiriasis, and your conjecture will be right. But some think, and those men of merited celebrity, thatmiteshave nothing to do in these and similar cases, for thatmaggotswere the parasites mistaken for lice. This, from the passage above quoted, appears to have been Dr. Willan's opinion, to which, in the letter so often referred to, Dr. Bateman subscribes; adding as a reason for excluding mites from being concerned, that "they are too minute, and never have been seen in such numbers as to be mistaken for lice." But both vary in size, some of the former being larger than some of the latter. And allowing them to be ever so minute, yet when they issue in swarms, as mites from a cheese, they would be very visible, were it only from their motion. Besides, as they are furnished with legs, their motions resemble those of lice infinitely more than do the contortions of maggots. So that a mite would be deemed a louse much sooner by an unentomological observer than would a maggot. Whether mites have ever been seen in such numbers as to be mistakenfor lice, is the point in question; and therefore, by itself, cannot be admitted for a valid argument. ThoughAcarus Scabieidoes not appear to swarm in ordinary cases, yet this is certainly no reason why other species may not do so. Where it has once made a settlement, how incredibly, and in how short a space of time, does theSiroor cheese-mite multiply!Acarus Destructorand many other species are equally rapid in their increase.—Millions of lice are said by Lafontaine, whom Hermann calls a very exact describer, to show themselves inPlica polonica, on the third day of the disease[135]; but whether the last-mentioned author be correct in thinking it more probable that they are mites[136], I have not the means of judging.
I shall now produce two instances where mites were evidently concerned. Dr. Mead, from theGerman Ephemerides, relates the miserable case of a French nobleman, from whose eyes, nostrils, mouth, and urinary passage animalcules of a red colour, and excessively minute, broke forth day and night, attended by the most horrible and excruciating pains, and at length occasioned his death. The account further says, that they were produced from his corrupted blood. This was probably a fancy originating in their red colour: but the whole history, whether we consider the size and colour of the animals, or the places from which they issue, is inapplicable tolarvæor maggots, and agrees very well withmites, some of which, particularlyLeptus autumnalis, are of a bright red colour. The other case, and a very similar one, is that recorded by Mouffet of Lady Penruddock; concerning whom he expressly tells us, that Acariswarmed in every part of her body—her head, eyes, nose, lips, gums, the soles of her feet, &c., tormenting her day and night, till, in spite of every remedy, all the flesh of her body being consumed, she was at length relieved by death from this terrible state of suffering. Mouffet attributes her disease to theAcarus Scabiei; but from the symptoms and fatal result it seems to have been a different and much more terrific animal. He supposes, in this instance, the insect to have been generated by drinking goat's milk too copiously. This, if correct, would lead to a conjecture that it might have been theA. Lactis, L.
These cases I hope will satisfy you that mites, as well as lice, are the cause of diseases in the human frame. This, indeed, as has been before observed, is allowed on all hands with respect to that of the itch; and it is, certainly, not more improbable that man should be exposed to the attack of several species of this genus, than that three or four kinds of Pediculus should infest him. If you are convinced by what I have written, you will concur with me in thinking that the one are as much entitled to give their name to the disease which they produce as the other; and the termAcariasis, by which, with due deference to medical men, I propose to distinguish generically all acarine diseases, will not be refused its place amongst yourGenera Morborum.
I shall now proceed to the remaining class of diseases mistaken for Phthiriasis; those, namely, which are produced bylarvæ. There are two terms employed by ancient authors,Eulæ(Ευλαι) andScolex(Σκωληξ), which seem properly to denote larvæ; but there is often such a want of precision in the language of writers unacquainted with Natural History, that it is very difficult to makeout what objects they mean; and expressions which, strictly taken, should be understood of larvæ, may probably sometimes have been used to denote the cause of either the pedicular or acarine disease.Eulæ, which term, though given by Hesychius as synonymous withScolex, is by Plutarch used as of different import[137], seems properly to mean those larvæ which are generated in dead carcases, at least so Homer has more than once applied it[138]: it is therefore a word of a much more restricted sense thanScolex, which probably belongs to the larvæ of every order of insects; for so Aristotle employs it, when he says that all insects produce aScolex, or are larviparous[139]. Yet when Homer compares Harpalion stretched dead upon the ground to aScolex[140], it should seem as if he used the word for an earth-worm, which Aristotle commonly calls by a figurative periphrasis, "Entrails of the earth[141]." In the Holy Scriptures this word is used to signify larvæ which prey upon and are the torment of living bodies[142]. It may on this account, perhaps, be regarded as generally meaning such larvæ, to whatever order or genus they belong.
Dr. Mead, therefore, is most probably right when he considers the disease stated by the ancients to be caused byEulæorScoleches, commonly translated worms, as distinct from Phthiriasis; and if so, the inhuman Pheretima, who swarmed withEulæ, and Herod Agrippa, who was eaten ofScoleches[143], were probably neither of them destroyed either by Pediculi or Acari, but bylarvæ or maggots. And when Galen prescribed a remedy for ulcers inhabited byScoleches, observing that animals similar to those generated by putrid substances are often found in abscesses, he probably meant the same thing. The proper appellation of this genus of diseases would beScolechiasis.
This dissertation may perhaps appear to you rather prolix and tedious: yet to settle the meaning of terms is of the first importance. To inquire what ancient writers intended by the words which they employ, and whether such as have been usually regarded as synonymous are really so, may often furnish us with a clue to some useful or interesting truth; and not seldom enable us to rescue their reputation from much of the censure which has been inconsiderately cast upon it. Because they did not know every thing, or so much as we do, we are too apt to think that they knew nothing. That they fell into very considerable errors, especially in subjects connected with Natural History, cannot be denied; but then it ought to be considered that they possessed scarcely any of those advantages by which we are enabled to penetrate into nature's secrets. The want of the microscope alone was an effectual bar to their progress in this branch of science. Yet, in some instances, when they took a general view of a subject, they appear to have had very correct ideas. This observation particularly applies to the philosopher of Stagyra, whose mighty mind and lyncean eye, in spite of those mists of prejudice and fable that enveloped the age in which he lived, enabled him in part to pierce through the gloom, and comprehend and behold the fair outline that gives symmetry, grace and beauty to the whole of nature's form, though he mistook,or was not able to trace out, her less prominent features and minor lineaments.
It is now time to return from this long digression, which however is closely connected with the subject of this letter, to the point from which I deviated. Taking my leave of the disgusting animals which gave rise to it, I proceed to call your attention to another of our pygmy tormentors, (Pulex irritans,) which, in the opinion of some, seems to have been regarded as an agreeable rather than a repulsive object. "Dear miss," said a lively old lady to a friend of mine, (who had the misfortune to be confined to her bed by a broken limb, and was complaining that the fleas tormented her,) "don't you likefleas? Well, I think they are the prettiest little merry things in the world.—I never saw a dull flea in all my life." The celebrated Willughby kept a favourite flea, which used at stated times to be admitted to suck the palm of his hand; and enjoyed this privilege for three months, when the cold killed it. And Dr. Townson, from the encomium which he bestows upon these vigilant little vaulters, as supplying the place of an alarum and driving us from the bed of sloth, should seem to have regarded them with feelings much more complacent than those of Dr. Clarke and his friends, when their hopes of passing "one night free from the attacks of vermin" were changed into despair by the information of the laughing Sheik, that "the king of the fleas held his court at Tiberias:" or than those of MM. Lewis and Clarke, who found them more tormenting than all the other plagues of the Missouri country, where they sometimes compel even the natives to shift their quarters. If you unhappilyview them in this unfavourable light, and have found ordinary methods unavailing for ridding yourself of these unbidden guests; I can furnish you with aprobatum estrecipe, which the first-mentioned traveller tells us the Hungarian shepherds (who seem to have been stupidly insensible to their value as alarums) find completely effectual to put to flight these insects and their neighbours the lice. This is not, as you may be tempted to think, by a remarkable attention to cleanliness.—Quite the reverse.—They grease their linen with hog's lard, and thus render themselves disgusting even to fleas! If this does not satisfy, I have another recipe in store for you. You may shoot at them with a cannon, as report says did Christina queen of Sweden, whose piece of artillery, of Lilliputian calibre, which was employed in this warfare, is still exhibited in the arsenal of Stockholm[144]. But, seriously, if you wish for an effectual remedy, that prescribed by old Tusser, in the following lines, will answer your purpose:
"While wormwood hath seed, get a handfull or twaine,To save against March, to make flea to refraine:Where chamber is sweeped, and wormwood is strown,No flea for his life dare abide to be known."
"While wormwood hath seed, get a handfull or twaine,To save against March, to make flea to refraine:Where chamber is sweeped, and wormwood is strown,No flea for his life dare abide to be known."
To this genus belongs an insect, abundant in the West Indies and South America, the attacks of which are infinitely more serious than those of the common flea. You will readily conjecture that I am speaking of the celebratedChigoeorJiggers, called alsoNigua,Tungua, andPique[145], (Pulex penetrans,) one of thedirest personal pests with which the sins of man have been visited. All disputes concerning the genus of this insect would have been settled long before Swartz's time, (who first gave a satisfactory description and figure of it, proving it to be aPulex, as has been observed above[146],) had success attended the patriotic attempt of the Capuchin friar recorded by Walton in hisHistory of St. Domingo, who brought away with him from that island a colony of these animals, which he permitted to establish themselves in one of his feet; but unfortunately for himself, and for science, the foot intrusted with the precious deposit mortified, was obliged to be amputated, and with all its inhabitants committed to the waves. According to Ulloa, and his opinion is confirmed by Jussieu, there are two South American species of this mischievous insect. It is described as generally attacking the feet and legs[147], getting, without being felt, between the skin and the flesh, usually under the nails of the toes, where it nidificates and lays its eggs; and if timely attention be not paid to it, which, as it occasions no other uneasiness than itching, (the sensation at first, I am assured, is rather pleasing than otherwise,) is sometimes neglected, it multiplies to such a degree, as to be attended by the most fatal consequences, often, as in the above instance, rendering amputation necessary, and sometimes causing death[148]. The female slaves in the West Indies are frequently employed to extract thesepests, which they do with uncommon dexterity. Yarico, so celebrated in prose and verse, performed this kind office for honest Ligon, who says, in hisHistory of Barbadoes, "I have had ten (Chegoes) taken out of my feet in a morning, by the most unfortunate Yarico, an Indian woman[149]." Humboldt observes, "that the whites born in the torrid zone walk barefoot with impunity in the same apartment where a European recently landed is exposed to the attack of this animal. TheNiguatherefore distinguishes what the most delicate chemical analysis could not distinguish, the cellular membrane and blood of a European from those of a creole white[150]."
You have already, perhaps, been satiated with the account before given of our enemies of theAcarustribe: there are a few, however, which I could not with propriety introduce there, as they do not take up their abode and breed in us, which nevertheless annoy us considerably. One of these is a hexapod so minute, that, were it not for the uncommon brilliancy of its colour, which is the most vivid crimson that can be conceived, it would be quite invisible. It is known by the name of the harvest-bug, (Leptus autumnalis,) and is so called, I imagine, from its attacking the legs of the labourers employed in the harvest, in the flesh of which it buries itself at the root of the hairs, producing intolerable itching, attended by inflammation and considerable tumours, and sometimes even occasioning fevers[151].—A similar insect is found in Brazil, abounding in the rainy season, particularly during the gleams of sunshine, or fine days that intervene; as small as a point, and moving very fast. Theseanimals get upon the linen and cover it in a moment; afterwards they insinuate themselves into the skin and occasion a most intolerable itching. They are with difficulty extracted, and leave behind them large livid tumours, which subside in a day or two. An insect very tormenting to the wood-cutters and the settlers on the Mosquito shore and the bay of Honduras, and called by themthe doctor, is thought to be synonymous with this[152].—More serious consequences have been known to follow the bite of another mite related to the above, if not the same species, common in Martinique, and called there theBête rouge. When our soldiers in camp were attacked by this animal, dangerous ulcers succeeded the symptoms just mentioned, which, in several cases, became so bad, that the limb affected was obliged to be taken off[153].
I was once collecting insects in Norwood, near London, when my hands were covered by a number of small hungry ticks, which were so greedy after blood, that they penetrated deep into my flesh, giving me no little pain; and it was not without difficulty that I extracted them. I suspect that this was the dog-tick (Ixodes Ricinus) which is often found on plants; but I am not certain, as I neglected to examine it, my attention at that time being almost wholly given toColeoptera. Lyonnet seems to have been attacked, in one of his entomological excursions, by the same or a similar insect, which he broke, so firmly had it fixed itself, in endeavouring to extract it; and he was obliged to lay open the place lestan abscess should be formed[154]. But the worst of all the tick tribe is the American (Ixodes americanus) described by Professor Kalm. This insect, which is related to the preceding, is found in the woods of North America, and is equally an enemy to man and beast. They are there so infinitely numerous, that if you sit down upon the ground, or upon the trunk of a tree, or walk with naked feet or legs, they will cover you, and, plunging their serrated rostrum into the bare places of the body, begin to suck your blood, going deeper and deeper till they are half buried in the flesh. Though at first they occasion no uneasiness, when they have thus made good their settlement, they produce an intolerable itching, followed by acute pain and large tumours. It is now extremely difficult to extract them, the animal rather suffering itself to be pulled to pieces than let go its hold; so that the rostrum and head being often left in the wound, produce an inflammation and suppuration which render it deep and dangerous. These ticks are at first very small, sometimes scarcely visible, but by suction will swell themselves out till they are as big as the end of one's finger, when they often fall to the ground of themselves[155]. The serrated haustellum of the ticks, which, like the barbed sting of a bee, cannot be extracted unless the animal cooperates, is well worth your inspection; and the species which infests our dogs is so common that you will have no difficulty in procuring one for examination.
I have now introduced you to the principal insects of theApteraorder of Linné, which, in spite of all his care and all his power, assail the lord of the creation, andmake him their food. You will here, however, perhaps accuse me of omitting one very prominent annoyer of our comfort and repose, which you think belongs to this tribe—the bed-bug (Cimex lectularius). When you are a more practised entomologist, you will see clearly that this, though it has no wings, appertains to another order: nevertheless it may be introduced here without impropriety. Though now too common and well known, in this country it was formerly a rare insect. Had it not, two noble ladies, mentioned by Mouffet, would scarcely have been thrown into such an alarm by the appearance of bug-bites upon them; which, until their fears were dispelled by their physician, who happened also to be a naturalist, they considered as nothing less than symptoms of the plague. Being shown the living cause of their fright, their fears gave place to mirth and laughter[156]. Commerce, with many good things, has also introduced amongst us many great evils, of which noxious insects form no small part; and one of her worst presents were doubtless the disgusting animals now before us. They seem, indeed, as the above fact proves, to have been productive of greater alarm at first than mischief, at least if we may judge from the change of name which took place upon their becoming common. Their original English name wasChincheorWall-louse[157]; and the termBug, which is a Celtic word, signifying a ghost or goblin, was applied to them after Ray's time, most probably because they were considered as "terrors bynight[158]." But however horrible bugs may have been in the estimation of some, or nauseating in that of others, many of the good people of London seem to regard them with the greatest apathy, and take very little pains to get rid of them; not generally, however, it is to be hoped, to such an extent as the predecessor of a correspondent in Nicholson'sJournal, who found his house so dreadfully infested by them, that it resembled the Banian hospital at Surat[159], all his endeavours to destroy them being at first in vain. And no wonder; for, as he learned from a neighbour, his predecessor would never suffer them to be disturbed or his bedsteads to be removed, till, in the end, they swarmed to an incredible degree, crawling up even the walls of his drawing-room; and after his death millions were found in his bed and chamber furniture[160].
The winged insects of the order to which the bed-bug belongs, often inflict very painful wounds.—I was once attacked by a small species, nearCimex Nemorum, L. (Hylophila, K.), which put me nearly to as much torture as the sting of a wasp. The water boatman (Notonectaglauca), an insect related to theCimicidæ, which always swims upon its back, made me suffer still more severely, as if I had been burned, by the insertion of its rostrum; but the wound was not followed by any inflammation; and long before me Willughby had made the same discovery and observation[161]. St. Pierre, in hisVoyage to Mauritius, mentions a species of bug found in that island, the bite of which is more venomous than the sting of a scorpion, and is succeeded by a tumour as big as the egg of a pigeon, which continues for four or five days. You are well acquainted with the history and properties of theRaia TorpedoandGymnotus electricus; but, I dare aver, have no idea that anyinsectpossesses their extraordinary powers.—Yet I can assure you, upon good authority, thatReduvius serratus, commonly known in the West Indies by the name of the wheel-bug, can, like them, communicate an electric shock to the person whose flesh it touches. The late Major-general Davies, of the Royal Artillery, well known as a most accurate observer of nature and an indefatigable collector of her treasures, as well as a most admirable painter of them, once informed me, that when abroad, having taken up this animal and placed it upon his hand, it gave him a considerable shock, as if from an electric jar, with its legs, which he felt as high as his shoulders; and, dropping the creature, he observed six marks upon his hand where the six feet had stood.
You may now possibly think that I have nearly gone through the catalogue of ourpersonalassailants of the insect tribes. If such, however, is your expectation, Ifear you will be disappointed, since I have many more, and some tremendous ones, to enumerate: but as a small compensation for such a detail of evils and injuries to which our species is exposed from foes seemingly so insignificant, and of acts of rebellion of the vilest and most despised of our subjects against our boasted supremacy, the objects to which I shall next call your attention are not, like most of our apterous enemies, calculated to excite disgust and nausea when we see them or speak of them; nor do they usually steal upon us during the silent hours of repose, (though I must except here the gnat or mosquito,) but are many of them very beautiful, and boldly make their attack upon us in open day, when we are best able to defend ourselves. Borne on rapid wings, wherever they find us, they endeavour to lay us under contribution, and the tribute they exact is our blood. Wonderful and various are the weapons that enable them to enforce their demand. What would you think of any large animal that should come to attack you with a tremendous apparatus of knives and lancets issuing from its mouth? Yet such are the instruments by means of which the fire-eyed and blood-thirsty horse-fly (Tabanus, L.) makes an incision in your flesh; and then, forming a siphon of them, often carries off many drops of your blood[162]. The pain they inflict, when they open a vein, is usually very acute. A fly of this kind not only occasioned Mr. Sheppard considerable pain by its bite, but also produced swelling and blackness round one eye; and the flesh of his cheek and chin was so enlarged from it as to hang down. And Mr. W. S. MacLeay thus describes to me the annoyance he sufferedfrom one of them. "I went down the other day to the country, and was fairly driven out of it by theHæmatopota pluvialis, which attacked me with such fury, that although I did not at last venture beyond the door without a veil, my face and hands were swelled to that degree as to be scarcely yet recovered from the effects of their venom. I was obliged on my return to town to stay two days at home. Whenever this insect bites me it has this effect, and I have never been able to discover any remedy for the torture it puts me to." In this country, however, the attacks of these flies are usually not frequent enough to make them more than a minor "misery of human life;" but the burning-fly (brulot) or sand-fly of America[163]and the West Indies, which seem to be the same insect, causes a much more intolerable anguish, which has been compared to what a red-hot needle or a spark of fire would occasion us to endure. Lambert, in hisTravels through Canada, &c. says, "They are so very small as to be hardly perceptible in their attacks; and your forehead will be streaming with blood before you are sensible of being amongst them[164]."—Yet we have one species (Stomoxys calcitrans) alluded to in a former letter as so nearly resembling the common house-fly[165], which, though its oral instruments are to appearance not near so tremendous, is a much greater torment than the horse-fly. This little pest, I speak feelingly, incessantly interrupts our studies and comfort in showery weather, making us even stamp like the cattle by its attacks onour legs; and, if we drive it away ever so often, returning again and again to the charge. In Canada they are infinitely worse. "I have sat down to write," says Lambert, (who though he calls it the house-fly is evidently speaking of the Stomoxys,) "and have been obliged to throw away my pen in consequence of their irritating bite, which has obliged me every moment to raise my hand to my eyes, nose, mouth, and ears in constant succession. When I could no longer write, I began to read, and was always obliged to keep one hand constantly on the move towards my head. Sometimes in the course of a few minutes I would take half a dozen of my tormentors from my lips, between which I caught them just as they perched[166]."
The swallow-fly (Craterina Hirundinis[167]), whose natural food is the bird after which it is named, has been known to make its repast on the human species. One found its way into a bed of the Rev. R. Sheppard, where it first, for several nights, sorely annoyed a friend of his, and afterwards himself, without their suspecting the culprit. After a close search, however, it was discovered in the form of this fly, which, forsaking the nest of the swallow, had by some chance taken its station between the sheets, and thus glutted itself with the blood of man.—In travelling between Edam and Purmerend in North Holland (July 21, 1815), in an open vehicle, I was much teased by another bird-fly (Ornithomyia avicularia) (two individuals of which I caught) alighting upon my head, and inserting its rostrum into my flesh.—Mr. Sheppard remarks, as a reason for this dereliction of their appropriate food, that no sooner does life depart from the birdthat these flies infest, than they immediately desert it and take flight, alighting upon the first living creature that they meet with; which if it be not a bird they soon quit, but, as it should seem from the above facts, not before they have made a trial how it will suit them as food.
But of all the insect-tormentors of man, none are so loudly and universally complained of as the species of the genusCulex, L., whether known by the name of gnats or mosquitos[168]. Pliny, after Aristotle, distinguishes well betweenHymenopteraandDiptera, when he says the former have their sting in their tail, and the latter in their mouth; and that to the one this weapon is given as the instrument of vengeance, and to the other of avidity[169]. But the instrument of avidity in the genus of which I am speaking, is even more terrible than that of vengeance in most insects that are armed with it: like the latter also, as appears from the consequent inflammation and tumour, it instills into its wound a poison; the principal use of which, however, is to render the blood more fluid and fitter for suction. This weapon, which is more complex than the sting of hymenopterous insects, consisting of five pieces besides the exterior sheath, some of which seem simply lancets, while others are barbed like the spicula of a bee's sting, is at once calculated for piercing the flesh and forming a siphonadapted to imbibe the blood[170]. There are several species of this genus whose bite is severe, but none is to be compared to the common gnat (Culex pipiens, L.), if, as has been generally affirmed, it be synonymous with the mosquito (though perhaps several species are confounded under both names); and to this, the most insatiable of blood-suckers, I shall principally direct your attention[171].
In this country they are justly regarded as no trifling evil; for they follow us to all our haunts, intrude into our most secret retirements, assail us in the city and in the country, in our houses and in our fields, in the sun and in the shade: nay, they pursue us to our pillows, and either keep us awake by the ceaseless hum of their droning pipe, and their incessant endeavours to fix themselves upon our face, or some uncovered part of our body; or, if in spite of them we fall asleep, awaken us by the acute pain which attends the insertion of their oral stings; attacking with most avidity the softer sex, and trying their temper by disfiguring their beauty. But although with us they are usually rather teasing than injurious; yet upon some occasions they have approached nearer to the character of a plague, and emulated with success the mosquitos of other climates. Thus, we are told that in the year 1736 they were so numerous, that vast columns of them were seen to rise in the air from Salisbury cathedral, which at a distance resembled columns of smoke, and occasioned many people to thinkthat the cathedral was on fire. A similar occurrence, in like manner giving rise to an alarm of the church being on fire, took place in July 1812 at Sagan in Silesia[172]. In the following year at Norwich, in May, at about six o'clock in the evening, the inhabitants of that city were alarmed by the appearance of smoke issuing from the upper window of the spire of the cathedral, for which at the time no satisfactory account could be given, but which was most probably produced by the same cause. And in the year 1766, in the month of August, they appeared in such incredible numbers at Oxford as to resemble a black cloud, darkening the air and almost totally intercepting the beams of the sun. One day, a little before sun-set, six columns of them were observed to ascend from the boughs of an apple-tree, some in a perpendicular and others in an oblique direction, to the height of fifty or sixty feet. Their bite was so envenomed, that it was attended by violent and alarming inflammation; and one when killed usually contained as much blood as would cover three or four square inches of wall[173]. Our great poet Spenser seems to have witnessed a similar appearance of them, which furnished him with the following beautiful simile:
As when a swarme of gnats at eventideOut of the fennes of Allan doe arise,Their murmuring small trumpets sownden wide,Whiles in the air their clust'ring army flies,That as a cloud doth seem to dim the skies;Ne man nor beast may rest or take repastFor their sharp wounds and noyous injuries.Till the fierce northern wind with blust'ring blastDoth blow them quite away, and in the ocean cast.
As when a swarme of gnats at eventideOut of the fennes of Allan doe arise,Their murmuring small trumpets sownden wide,Whiles in the air their clust'ring army flies,That as a cloud doth seem to dim the skies;Ne man nor beast may rest or take repastFor their sharp wounds and noyous injuries.Till the fierce northern wind with blust'ring blastDoth blow them quite away, and in the ocean cast.
In Marshland in Norfolk, as I learn from a lady who had an opportunity of personal inspection, the inhabitants are so annoyed by the gnats, that the better sort of them, as in many hot climates, have recourse to a gauze covering for their beds, to keep them off during the night. Whether this practice obtains in other fen districts I do not know.
But these evils are of small account compared with what other countries, especially when we approach the poles or the line, are destined to suffer from them; for there they interfere so much with ease and comfort, as to become one of the worst of pests and a real misery of human life. We may be disposed to smile perhaps at the story Mr. Weld relates from General Washington, that in one place the mosquitos were so powerful as to pierce through his boots[174](probably they crept within the boots): but in various regions scarcely any thing less impenetrable than leather can withstand their insinuating weapons and unwearied attacks. One would at first imagine that regions where the polar winter extends its icy reign would not be much annoyed by insects: but however probable the supposition, it is the reverse of fact, for nowhere are gnats more numerous. These animals, as well as numbers of theTipulariæof Latreille, seem endowed with the privilege of resisting any degree of cold, and of bearing any degree of heat. In Lapland their numbers are so prodigious as to becompared to a flight of snow when the flakes fall thickest, or to the dust of the earth. The natives cannot take a mouthful of food, or lie down to sleep in their cabins, unless they be fumigated almost to suffocation. In the air you cannot draw your breath without having your mouth and nostrils filled with them; and unguents of tar, fish-grease, or cream; or nets steeped in fetid birch-oil, are scarcely sufficient to protect even the case-hardened cuticle of the Laplander from their bite[175]. In certain districts of France, the accurate Reaumur informs us that he has seen people whose arms and legs have become quite monstrous from wounds inflicted by gnats; and in some cases in such a state as to render it doubtful whether amputation would not be necessary[176]. In the neighbourhood of the Crimea the Russian soldiers are obliged to sleep in sacks to defend themselves from the mosquitos; and even this is not a sufficient security, for several of them die in consequence of mortification produced by the bites of these furious blood-suckers. This fact is related by Dr. Clarke, and to its probability his own painful experience enabled him to speak. He informs us that the bodies of himself and his companions, in spite of gloves, clothes, and handkerchiefs, were rendered one entire wound, and the consequent excessive irritation and swelling excited a considerable degree of fever. In a most sultry night, when not a breath of air was stirring, exhausted by fatigue, pain, and heat, he sought shelter in his carriage: and, though almost suffocated, could not venture to open a window for fear of the mosquitos. Swarms nevertheless found their wayinto his hiding-place; and, in spite of the handkerchiefs with which he had bound up his head, filled his mouth, nostrils, and ears. In the midst of his torment he succeeded in lighting a lamp, which was extinguished in a moment by such a prodigious number of these insects, that their carcases actually filled the glass chimney, and formed a large conical heap over the burner. The noise they make in flying cannot be conceived by persons who have only heard gnats in England. It is to all that hear it a most fearful sound[177]. Travellers and mariners who have visited warmer climates give a similar account of the torments there inflicted by these little demons. One traveller in Africa complains that after a fifty miles journey they would not suffer him to rest, and that his face and hands appeared, from their bites, as if he was infected with the small-pox in its worst stage[178]. In the East, at Batavia, Dr. Arnold, a most attentive and accurate observer, relates that their bite is the most venomous he ever felt, occasioning a most intolerable itching, which lasts several days. The sight or sound of a single one either prevented him from going to bed for a whole night, or obliged him to rise many times. This species, which I have examined, is distinct from the common gnat, and appears to be nondescript. It approaches nearest toC. annulatus, but the wings are black and not spotted. And Captain Stedman in America, as a proof of the dreadful state to which he and his soldiers were reduced by them, mentions that they were forced to sleep with their heads thrust into holes made in the earth with their bayonets, and their necks wrapped round with their hammocks[179].
From Humboldt also we learn that "between the little harbour of Higuerote and the mouth of the Rio Unare the wretched inhabitants are accustomed to stretch themselves on the ground, and pass the night buried in the sand three or four inches deep, leaving out the head only, which they cover with a handkerchief." This illustrious traveller has given an account in detail of these insect plagues, by which it appears that amongst them there are diurnal, crepuscular, and nocturnal species, or genera: theMosquitosorSimuliaflying in the day; theTemporaneros, probably a kind ofCulex, flying during twilight; and theZancudosorCulicesin the night. So that there is no rest for the inhabitants from their torment day or night, except for a short interval between the retreat of one species and the attack of another. We learn from this author that the sting or bite of theSimuliumis as bad as that of theStomoxysbefore noticed[180].
It is not therefore incredible that Sapor, king of Persia, as is related, should have been compelled to raise the siege of Nisibis by a plague of gnats, which attacking his elephants and beasts of burthen, so caused the rout of his army, whatever we may think of the miracle to which it was attributed[181]; nor that the inhabitants of various cities, as Mouffet has collected from different authors[182], should, by an extraordinary multiplication of this plague, have been compelled to desert them; orthat by their power to do mischief, like other conquerors who have been the torment of the human race, they should have attained to fame, and have given their name to bays, towns, and even to considerable territories[183].
And now, which seems to you the greater terror, that the forest should resound with the roar of the lion or the tiger, or with the hum of the gnat? Which evil is most to be deprecated, the neighbourhood of these ferocious animals, terrible as they are for their cruelty and strength, or to live amidst the polar or tropical myriads of mosquitos, and be subject to the torture of their incessant attacks? When you consider that from the one, prudence and courage may secure or defend us without any material sacrifice of our daily comforts; while to be at rest from the other, we must either render ourselves disgusting by filthy unguents, or be suffocated by fumigations, or be content to be bound, head, hand and foot, shut out from the respiration of the common air, and even thus scarcely escape from their annoyance; you will feel convinced that the former is the more tolerable evil of the two, and be inclined to think that those cities, from which the lions were driven away by the more powerful gnats, were no great gainers by the exchange[184]. With what grateful hearts ought the privileged inhabitants of these happy islands to acknowledge and glorify the goodness of that kind Providence which has distinguished us from the less favoured nations of the globe, by what may be deemed an immunity from this tormenting pest! for the inroads which they make on our comfort, when contrastedwith what so many other people of every climate suffer from them, are mere nothings. When we behold on one side of us the ravages of the wide-wasting sword, on another those of infectious disease or pestilence, on a third famine destroying its myriads, and on a fourth life rendered uncomfortable by the terror of "noisome beasts," and the attack of noxious insects: and when we look at home and see every one eating his bread in peace, protected in his enjoyments by equal laws executed by a mild government under a paternal king, without fearing the sword of the oppressor; not scourged by pestilence or famine, exposed to the attack of no ferocious animal, and comparatively speaking but slightly visited by the annoyance of insect tormentors; and especially when we further reflect that it is his mercy and not our merits which has induced him thus to overwhelm us with blessings, while other countries have been made to drink deep of the cup of his fury, we shall see reason for an increased degree of thankfulness and gratitude, and, instead of repining, be well content with our lot, though our offences have not wholly been passed over, and we have been "beaten with few stripes."
Besides the insects that seek to make us their food, there are others, which, although we are apt to regard them with the greatest horror, do not attack us with this view, but usually to revenge some injury which they have received, or apprehend from us. Foremost in the list of these are those with four wings, which, according to the observation of Pliny before quoted, carry their weapon, an instrument of revenge, in theirtail. These all belong to the Linnean orderHymenoptera; and thetremendous arms with which they annoy us, are two darts finer than a hair, furnished on their outer side at the end with several barbs not visible to the naked eye, and each moving in the groove of a strong and often curved sheath, frequently mistaken for the sting, which, when the darts enter the flesh, usually injects a drop of subtle venom, furnished from a peculiar vessel in which it is secreted, into the wound, occasioning, especially if the darts be not extracted, a considerable tumour, accompanied by very acute pain. Many insects are thus armed and have this power. Twice I have been stung by an Ichneumon; first by one with a concealed sting, and afterwards by another of the family ofPimpla Manifestator, with a very long exerted one. I had held the insect by its sting, which it withdrew from between my fingers with surprising force, and then, as if in revenge, stung me.Pompilus viaticus, one of the spider-wasps, once, in this way, gave me acute pain. Mr. W. S. MacLeay states that at the Havana he was once stung by a giganticPompilus(probablyP. Heros), from which he suffered a very short-lived pain, but the wound bled as if punctured by a pin. The bleeding he conjectures carried off the venom. But the insects which in this respect principally attract our notice by exciting our fears, are the hive-bee, the wasp, and the hornet. The first of these, thebee, sometimes manifests an antipathy to particular individuals, whom it attacks and wounds without provocation; but the two last, though apparently the most formidable, are not so ill-tempered as they are conceived to be, seldom molesting those who do not first interfere with or disturb them. We learn from Scripture that thehornet(but whether it was the common species is uncertain) was employed by Providence todrive out the impious inhabitants of Canaan, or subdue them under the hand of the Israelites[185].—The effect produced by the sting of these animals is different in different persons. To some they occasion only a very slight inconvenience or a momentary pain; others feel the smart of the wounds which they inflict for several days, and are thrown into fevers by them; and to some they have even proved fatal[186]. Yet these insects are certainly, in general, but a trifling evil. They become, however, especiallywasps, a very serious one to many, from the mere dread of being stung by them, even though they should not carry their fears to the same length with the lady mentioned by Dr. Fairfax[187], in thePhilosophical Transactions, who had such a horror of them, that during the season in which they abound in houses, she always confined herself to her apartment.
Antsare insects of this order, which, though our indigenous species may be regarded as harmless, in some countries are gifted with double means of annoyance, both from their sting and their bite. A green kind in New South Wales was observed by Sir Joseph Banks to inflict a wound scarcely less painful than the sting of a bee[188]. Another, from the intolerable anguish occasioned by its bite, which resembles that produced by a spark of fire, and seems attended by venom, is called the fire-ant. Captain Stedman relates that this caused a whole company of soldiers to start and jump about as if scalded with boiling water; and its nests were so numerous that it was not easy to avoid them[189]. We are told of a third species, which emulates the scorpion inthe malignity of its sting or bite[190]. Knox, in his account of Ceylon, mentions a black ant, called by the nativesCoddia, which he says "bites desperately, as bad as if a man were burnt by a coal of fire; but they are of a noble nature, and will not begin unless you disturb them." The reason the Cinghalese assign for the horrible pain occasioned by their bite is curious, and will serve to amuse you. "Formerly these ants went to ask a wife of theNoya, a venomous and noble kind of snake; and because they had such a high spirit to dare to offer to be related to such a generous creature, they had this virtue bestowed upon them, that they should sting after this manner. And if they had obtained a wife of the Noya, they should have had the privilege to sting full as bad as he[191]." Stedman's story of a large ant that stripped the trees of their leaves, to feed, as was supposed, a blind serpent under ground[192], is somewhat akin to this: as is also another, related to me by a friend of mine, of a species of Mantis, now in my cabinet, taken in one of the Indian islands, which, according to the received opinion amongst the natives, was the parent of all their serpents. Whence, unless perhaps from their noxious qualities, could this idea of a connexion between insects and these reptiles be derived? But to return from this digression——Madame Merian's Ant of Visitation (Œcodoma cephalotes) will be considered in a subsequent letter: but I cannot here omit a circumstance mentioned by Don Felix de Azara, a late Spanish traveller, who confirms her account,—that these animals are so alarming and tremendous in their attacks, that ifthey enter a house in the night, the inhabitants are obliged to rise with all speed and run off in their shirts.
I must next direct your attention to an insect, which perhaps more than any other has in every age been an object of terror and abhorrence—I mean the redoubtedscorpion. And though I shall not, with Aristotle, tell you of Persian kings employing armies for several days in destroying them; or, with Pliny, of countries that they have depopulated; yet my account will not be devoid of that species of interest which the dread of its power to do us injury imparts to any object. Could you see one of these ferocious animals, perhaps a foot in length, a size to which they sometimes attain, advancing towards you in their usual menacing attitude, with its claws expanded, and its many-jointed tail turned over its head; were your heart ever so stout, I think you would start back and feel a horror come across you; and, though you knew not the animal, you would conclude that such an aspect of malignity must be the precursor of malignant effects. Nor would you be mistaken, as you will presently see. This alarming animal, though like hymenopterous insects it is armed with a sting, is in no respect related to that order, and forms the only genus, at present known, of the others that is so armed. Even its sting is totally different from that of bees, wasps, and other Hymenoptera, being more analogous to the venomous tooth of serpents; it wounds us with no barbed darts concealed in a sheath, but only with a simple incurved mucro terminating an ampullaceous joint. Two orifices, or according to some three, are said to instill the poison, which, we are informed, is sometimes as white as milk. This venom in our Europeanspecies is seldom attended, except to minor animals, by any very serious consequences; yet when it is communicated by the scorpion of warmer climates it produces more baneful effects. The sting of certain kinds common in South America causes fevers, numbness in various parts of the body, tumours in the tongue, and dimness of sight, which symptoms last from twenty-four to forty-eight hours. The only means of saving the lives of our soldiers who were stung by them in Egypt, was amputation. One species is said to occasion madness; and the black scorpion, both of South America and Ceylon, frequently inflicts a mortal wound[193]. No known animal is more cruel and ferocious in its manners; they kill and devour their own young without pity as soon as they are born, and they are equally savage to their fellows when grown up. Terrible however and revolting as these creatures appear, we are gravely told by Naudé, that there is a species of scorpion in Italy which is domesticated, and put between the sheets to cool the beds during the heats of summer[194]!!
I must next say something of insects that annoy us solely by theirjaws. Of this description isGaleodes araneoideswhich is related to the scorpion, although devoid of a sting. The bite of this animal, which is a native of the Cape of Good Hope and of Russia[195], is represented to be often fatal both to man and beast. Anotherspecies ofGaleodesis described by Professor Lichtenstein, which, from the trivial name that he has given it (fatalis), may be supposed to be as venomous as the former[196].
The bite of one of the centipedes (Scolopendra morsitans)—the under-jaws, or rather arms, of which are armed with a strong claw, furnished like the sting of the scorpion with an orifice, visible under a common lens[197], from which poison issues—is less tremendous than that of the animal last mentioned: but though not mortal, its wounds are more painful than those produced by the sting of the scorpion; and as these animals creep every where, even into beds, they must be very annoying in warm climates where they abound. Dr. Martin Lister, in hisTravels, has given us a figure of an insect related to this genus, that he saw in Plumier's collection, which appears to have been eighteen inches in length, and three quarters of an inch in width, having ninety-five legs on each side, the first eight of which are armed with double claws, and two inches of the tail being without legs. It may form a distinct genus, and is probably a native of South America. Yet even this monstrous insect is nothing to those at Carthagena, mentioned by Ulloa, (if indeed we may credit his account, or if his translator has not mistaken his meaning,) which sometimes exceeded a yard in length and five inches in breadth! The bite of this gigantic serpent-like creature, he tells us, is mortal, as well it may, if a timely remedy be not applied. From its cylindrical form it should be a Julus[198].
In this catalogue of noxious insects I must not omitthose which every where force themselves upon our notice, and are viewed with general disgust. I mean the numerous family of Arachne, the insidious spiders. Few of these, however, are really personal assailants of man. The principal is that which has given rise to so much discussion, and has so much employed the pens of naturalists and physicians—the famousTarentula(Lycosa Tarentula). The effects ascribed to its wounds, and their wonderful cure supposed to be wrought by music and dancing, have long been celebrated: but after all there seems to have been more of fraud than of truth in the business; and the whole evil appears to consist in swelling and inflammation. Dr. Clavitio submitted to be bitten by this animal, and no bad effects ensued; and the Count de Borch, a Polish nobleman, bribed a man to undergo the same experiment, in whom the only result was a swelling in the hand, attended by intolerable itching. The fellow's sole remedy was a bottle of wine, which charmed away all his pain without the aid of pipe and tabor[199].
There is however a spider (Theridium13-guttatum) the bite of which is said to be very dangerous, and even mortal. Thiébaut de Berneaud, in hisVoyage to Elba[200], affirms that in the Volterrano he knew that several country people and domestic animals died in consequence of it. And according to Mr. Jackson, a spider, called there theTendaraman, is found in Marocco which has venomous powers equally formidable. The bite of this insect, which is about the size and colour of a hornet but rounder, and spins a web so fine as to be almost invisible, is said to be so poisonous that the person bittensurvives but a few hours. In the cork forests the sportsman, eager in his pursuit of game, frequently carries away on his garments this fatal insect, which is asserted always to make towards the head before inflicting its deadly wound[201].
I suspect you will think this list long enough; and I believe it includes the most remarkable insects that assail the surface of our bodies, to answer either the demands of hunger or the stimulus of revenge. There is however a third class of insect annoyers, as I observed at the beginning of this letter, which, though they neither make us their food, nor attack us under the impulse of fear or revenge, incommode us extremely in other ways. These must now be detailed to you.
How extremely unpleasant is the sensation which that very minute fly,Thrips physapus, excites in sultry weather, merely by creeping over our skin! I have sometimes found this almost intolerable. A similar torment reckoned by Ulloa a kind of Mosquito, infests the inhabitants of Carthagena in South America. They are there calledMantas blancas, and creeping between the threads of the gauze curtains that keep off the former pest, though they do not bite, occasion an itching that is dreadfully tormenting[202]. But these are nothing compared with the teasing attacks of another gnat (Simulium reptans), which, as Linné informs us, who misnamed it a Culex, is so incredibly numerous in Lapland, as entirelyto cover a man's body, turning a white dress into a black one, occupying the whole atmosphere, filling the mouth, nostrils, eyes, and ears of travellers, and thus preventing respiration, and almost choking them. These little animals, he says, do not bite, but torture incessantly by their titillation[203].—In New South Wales a small ant was observed by Sir Joseph Banks, inhabiting the roots of a plant, which when disturbed rushed out by myriads, and running over the uncovered parts of the body produced a sensation of this kind that was worse than pain.
The common house-fly is with us often sufficiently annoying at the close of summer; but we know nothing of it as a tormentor compared with the inhabitants of southern Europe.—"I met (says Arthur Young in his interestingTravels through France) between Pradelles and Thuytz, mulberries and flies at the same time; by the termfliesI mean those myriads of them which form the most disagreeable circumstance of the southern climates. They are the first torments in Spain, Italy, and the Olive district of France: it is not that they bite, sting, or hurt, but they buzz, tease, and worry: your mouth, eyes, ears, and nose, are full of them: they swarm on every eatable,—fruit, sugar, milk, every thing is attacked by them in such myriads, that if they are not incessantly driven away by a person who has nothing else to do, to eat a meal is impossible. They are however caught on prepared paper and other contrivances with so much ease and in such quantities, that were it not from negligence, they could not abound in such incredible quantities. If I farmed in these countries, I think I shouldmanure four or five acres every year with dead flies.—I have been much surprised that the late learned Mr. Harmer should think it odd to find, by writers who treated of southern climates, that driving away flies was an object of importance. Had he been with me in Spain and in Languedoc in July and August, he would have been very far from thinking there was any thing odd in it[204]."
Our friend Captain Green, of the sixth regiment of the East India Company's native troops, relates to me, that in India, when the mangoes are ripe, which is the hottest part of the summer, a very minute black fly makes its appearance, which, because it flies in swarms into the eyes, is very troublesome, and causes much pain, is called there theeye-fly. At this season the eyes are attacked by a disease, supposed to be occasioned by eating the mangoes, but more probably the result of the irritation produced by the fly in question, which, however, they admit, carries the infection from one person to another.
You know that the hairs taken from the pods ofDolichos pruriensandurens, L., commonly calledCowhageandCow-itch[205], occasion a most violent itching, but perhaps are not aware that those of thecaterpillarsof several Moths will produce the same disagreeable effect. One of these is the procession moth, (Lasiocampa processionea) of which Reaumur has given so interestingan account. In consequence of their short stiff hairs sticking in his skin, after handling them, he suffered extremely for several days; and being ignorant at first of the cause of the itching, and rubbing his eyes with his hands, he brought on a swelling of the eye-lids, so that he could scarcely open them. Ladies were affected even by going too near the nest of the animal, and found their necks full of troublesome tumours, occasioned by short hairs, or fragments of hair, brought by the wind[206]. Of this nature also is the famous Pityocampa of the ancients, the moth of the fir (Lasiocampa Pityocampa), the hairs of which are said to occasion a very intense degree of pain, heat, fever, itching and restlessness. It was accounted by the Romans a very deleterious poison, as is evident from the circumstance of the Cornelian law "De sicariis" being extended to persons who administeredPityocampa[207].
In these cases the injury is the consequence of irritation produced by the hair of the animal; but there are facts on record, which prove that the juices of many insects are equally deleterious. Amoreux, from a work of Turner, an English writer on cutaneous diseases, has given the following remarkable history of the ill effects produced by those ofspiders. When Turner was a young practitioner, he was called to visit a woman, whose custom it was, every time she went into the cellar with a candle, to burn the spiders and their webs. She had often observed, when she thus cruelly amused herself, that the odour of the burning spiders had so much affected her head, that all objects seemed to turn round, which was occasionally succeeded by faintings, coldsweats, and slight vomitings: but, notwithstanding this, she found so much pleasure in tormenting these poor animals, that nothing could cure her of this madness, till she met with the following accident: The legs of one of these unhappy spiders happened to stick in the candle, so that it could not disengage itself; and, the body at length bursting, the venom was ejaculated into the eyes and upon the lips of its persecutrix. In consequence of this, one of the former became inflamed, the latter swelled excessively, even the tongue and gums were slightly affected, and a continual vomiting attended these symptoms. In spite of every remedy the swelling of the lips continued to increase, till at length an old woman, by the simple application for fifteen days of the leaves and juice of plantain, together with some spider's web, ran away with all the glory of the cure[208]. Ulloa gives us a remarkable account of a species of spider, or perhaps mite, of a fiery red colour, common in Popayan, calledCoyaorCoyba, and usually found in the corners of walls and among the herbage, the venom of which is of such malignity, that on crushing the insect, if any fall on the skin of either man or beast, it immediately penetrates into the flesh, and causes large tumours, which are soon succeeded by death. Yet, he further observes, if it be crushed between the palms of the hands, which are usually callous, no bad consequence ensues. People who travel along the valleys of the Neyba, where these insects abound, are warned by their Indian attendants, if they feel any thing stinging them, or crawling on their neck or face, not so much as to lift up their hand to the place, the texture of the Coya being so delicate that the least force causes them to burst, without which there is nodanger, as they seem otherwise harmless animals. The traveller points out the spot where he feels the creature to one of his companions, who, if it be a Coya, blows it away. If this account does not exaggerate the deleterious quality of the juices of this insect, it is the most venomous animal that is known; for he describes it as much smaller than a bug. The only remedy to which the natives have recourse for preventing the ill effects arising from its venom is, on the first appearance of the swelling, to swing the patient over the flame of straw or long grass, which they do with great dexterity: after this operation he is reckoned to be out of danger[209].—The poisoned arrows which Indians employ against their enemies have been long celebrated. The Coya may, in the western world, have furnished the poison for this purpose. An author quoted in Lesser tells us that an ant as big as a bee is sometimes used, and that the wound inflicted by weapons tinctured with their venom is incurable. Patterson also gives a recipe by which the natives of the southern extremity of Africa prepare what they reckon the most effectual poison for the point of their arrows. They mix the juice of a species of Euphorbia, and a caterpillar that feeds on a kind of sumach (Rhus, L.), and when the mixture is dried it is fit for use[210].
And now I think you will allow that I have made out a tolerable list of insects that attack or annoy man's body externally, and a sufficiently doleful history of them. That the subject, however, may be complete, I shall next enumerate those that, not content with afflicting him withexteriorpain or evil, whether on the surface or under the skin, bore into his flesh, descend even into his stomach and viscera; derange his whole system, and thus often occasion his death. The punitive insects here employed are usually larvæ of the various orders, and they are the cause of that genus of diseases I before noticed, and proposed to callScolechiasis.