Chapter VII: Letter IV: Injuries Caused by Insects (2)

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 think that 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 eventide
Out 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 repast
For their sharp wounds and noyous injuries.
Till the fierce northern wind with blust'ring blast
Doth 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 the _Tipulariæ_ of 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 be compared 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 way into 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 to _C. 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: the _Mosquitos_ or _Simulia_ flying in the day; the _Temporaneros_, probably a kind of _Culex_, flying during twilight; and the _Zancudos_ or _Culices_ in 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 the _Simulium_ is as bad as that of the _Stomoxys_ before 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; or that 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 contrasted with 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."

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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 their _tail_. These all belong to the Linnean order _Hymenoptera_; and the tremendous 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 of _Pimpla 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 gigantic _Pompilus_ (probably _P. 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, the _bee_, 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 the _hornet_ (but whether it was the common species is uncertain) was employed by Providence to drive 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, especially _wasps_, 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 the _Philosophical 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.

_Ants_ are 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 in the malignity of its sting or bite[190]. Knox, in his account of Ceylon, mentions a black ant, called by the natives _Coddia_, 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 the _Noya_, 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 if they 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 redoubted _scorpion_. 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 European species 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 their _jaws_. Of this description is _Galeodes araneoides_ which 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. Another species of _Galeodes_ is 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 his _Travels_, 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 omit those 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 famous _Tarentula_ (_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 (_Theridium_ 13_-guttatum_) the bite of which is said to be very dangerous, and even mortal. Thiébaut de Berneaud, in his _Voyage 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 the _Tendaraman_, 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 bitten survives 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].

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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 called _Mantas 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 entirely to 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 interesting _Travels through France_) between Pradelles and Thuytz, mulberries and flies at the same time; by the term _flies_ I 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 should manure 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 the _eye-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 of _Dolichos pruriens_ and _urens_, L., commonly called _Cowhage_ and _Cow-itch_[205], occasion a most violent itching, but perhaps are not aware that those of the _caterpillars_ of several Moths will produce the same disagreeable effect. One of these is the procession moth, (_Lasiocampa processionea_) of which Reaumur has given so interesting an 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 administered _Pityocampa_[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 of _spiders_. 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, cold sweats, 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, called _Coya_ or _Coyba_, 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 no danger, 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 with _exterior_ pain 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 call _Scolechiasis_.

I shall begin my account with the first order of Linné, because people in general seem not aware that any _beetles_ make their way into the human _stomach_. Yet there is abundant evidence, which proves beyond controversy that the meal-worm (_Tenebrio Molitor_), although its usual food is flour, has often been voided both by male and female patients; and in one instance is stated to have occasioned death[211]. How these grubs should get into the stomach it is difficult to say--perhaps the eggs may have been swallowed in some preparation of flour. But that the animal should be able to sustain the heat of this organ, so far exceeding the temperature to which it is usually accustomed, is the most extraordinary circumstance of all.--Dr. Martin Lister, who to the skill of the physician added the most profound knowledge of nature, mentions an instance, communicated to him by Mr. Jessop, of a girl who voided three hexapod larvæ similar to what are found in the carcases of birds[212], probably belonging either to the genus _Dermestes_, or _Anthrenus_: and in the _German Ephemerides_ the case also of a girl is recorded, from an abscess in the _calf_ of whose _leg_ crept black worms resembling beetles[213].

The larvæ of some beetle, as appears from the description, seem to have been ejected even from the _lungs_. Four of these, of which the largest was nearly three quarters of an inch long, were discovered in the mucus expelled after a severe fit of coughing by a lady afflicted with a pulmonary disease; and similar larvæ of a smaller size were once afterwards discharged in the same way[214].

No one would suppose that _caterpillars_, which feed upon vegetable substances, could be met with alive in the stomach; yet Dr. Lister gives an account of a boy who vomited up several, which, he observes, had sixteen legs[215]. The eggs perhaps might have been swallowed in salad; and, as vegetables make a part of most people's daily diet, enough might have passed into the stomach to support them when hatched.--Linné tells us that the caterpillar of a moth (_Aglossa pinguinalis_), common in houses, has also been found in a similar situation, and is one of the worst of our insect infesters.--In a very old tract, which gives a figure of the insect, a caterpillar of the almost incredible length of the middle finger is said to have been voided from the _nostrils_ of a young man long afflicted with dreadful pains in his head[216].--But the most extraordinary account with respect to lepidopterous larvæ (unless he has mistaken his insects) is given by Azara, the Spanish traveller before quoted; who says that in South America there is a large brown _moth_, which deposits its young in a kind of saliva upon the flesh of persons who sleep naked; these introduce themselves under the skin without being perceived, where they occasion swelling attended by inflammation and violent pain. When the natives discover it, they squeeze out the larvæ, which usually amount to five or six[217].

But amongst all the orders, none is more fruitful in devourers of man than the _Diptera_. The Gad-fly (_Œstrus_, L.) you have, doubtless, often heard of, and how sorely it annoys our cattle and other quadrupeds; but I suspect have no notion that there is a species appropriated to man. The existence, indeed, of this species seems to have been overlooked by entomologists (though it stands in Gmelin's edition of the _Systema Naturæ_[218], upon the authority of the younger Linné,) till Humboldt and Bonpland mentioned it again. Speaking of the low regions of the torrid zone, where the air is filled with those myriads of mosquitos which render uninhabitable a great and beautiful portion of the globe, they observe that to these may be joined the _Œstrus Hominis_, which deposits its eggs in the skin of man, causing there painful tumours[219]. Gmelin says that it remains beneath the skin of the abdomen six months, penetrating deeper, if it be disturbed, and becoming so dangerous as sometimes to occasion death. The imago he describes as being of a brown colour, and about the size of the common house-fly; so that it is a small species compared with the rest of the genus. Even the gad-fly of the ox, leaving its proper food, has been known to oviposit in the jaw of a woman, and the bots produced from the eggs finally caused her death[220].--Other flies also of various kinds thus penetrate into us, either preying upon our flesh, or getting into our intestines. Leeuwenhoek mentions the case of a woman whose leg had been enlarging with glandular bodies for some years. Her surgeon gave him one that he had cut from it, in which were many small maggots: these he fed with flesh till they assumed the pupa, when they produced a fly as large as the flesh-fly[221].--A patient of Dr. Reeve of Norwich, after suffering for some time great pain, was at last relieved by voiding a considerable number of maggots, which agree precisely with those described by De Geer as the larvæ of his _Musca domestica minor_, (_Anthomyia canicularis_, Meig.) a fly which he speaks of as very common in apartments[222].--In Paraguay the flesh-flies are said to be uncommonly numerous and noxious. Azara relates[223] that, after a storm, when the heat was excessive, he was assailed by such an army of them, that in less than half an hour his clothes were quite white with their eggs, so that he was forced to scrape them off with a knife; adding, that he has known instances of persons, who, after having bled at the nose in their sleep, were attacked by the most violent headaches; when at length several great maggots, the offspring of these flies, issuing from their nostrils, gave them relief.--In Jamaica a large blue fly buzzes about the sick in the last stages of fever; and when they sleep or doze with their mouths open, the nurses find it very difficult to prevent these flies from laying their eggs in the nose, mouth, or gums. An instance is recorded of a lady who, after recovering from a fever, fell a victim to the maggots of this fly, which from the nose found their way through the _os cribriforme_ into the cavity of the skull, and afterwards into the brain[224]. One of the most shocking cases of _Scolechiasis_ I ever met with is related in Bell's _Weekly Messenger_ in the following words: "On Thursday, June 25, died at Asbornby, (_Lincolnshire_) John Page, a pauper belonging to Silk-Willoughby, under circumstances truly singular. He being of a restless disposition, and not choosing to stay in the parish workhouse, was in the habit of strolling about the neighbouring villages, subsisting on the pittance obtained from door to door: the support he usually received from the benevolent was bread and meat; and after satisfying the cravings of nature, it was his custom to deposit the surplus provision, particularly the meat, betwixt his shirt and skin. Having a considerable portion of this provision in store, so deposited, he was taken rather unwell, and laid himself down in a field in the parish of Scredington--when from the heat of the season at that time, the meat speedily became putrid, and was of course struck by the flies: these not only proceeded to devour the inanimate pieces of flesh, but also literally to prey upon the living substance; and when the wretched man was accidentally found by some of the inhabitants, he was so eaten by the maggots that his death seemed inevitable. After clearing away as well as they were able these shocking vermin, those who found Page conveyed him to Asbornby, and a surgeon was immediately procured, who declared that his body was in such a state that dressing it must be little short of instantaneous death; and in fact the man did survive the operation but a few hours. When first found, and again when examined by the surgeon, he presented a sight loathsome in the extreme; white maggots of enormous size were crawling in and upon his body, which they had most shockingly mangled, and the removing of the external ones served only to render the sight more horrid[225]."--A medical friend of mine, at Ipswich, gave me this winter an apode larva voided by a person of that place with his urine, which I now preserve in spirits and can show you when you visit me. It appears to me to belong to the _Diptera_ order, yet not to the fly tribes (_Tanystoma_, Latr.), but rather to the _Tipulariæ_ of that author, with which however it does not seem to agree so entirely as to take away all doubt. It is a very singular larva, and I can find none in any author that I have had an opportunity of consulting which at all resembles it. That you may know it, should you chance to meet with it, I shall here describe it. _Body_, three fourths of an inch in length, and about a line in breadth; opaque, of a pale yellow colour; cylindrical, tapering somewhat at each extremity; consisting of twenty articulations without the head: _Head_ reddish brown, heartshaped, much smaller than the following joint; armed with two unguiform mandibles; with a biarticulate palpus attached exteriorly to the base of each. These mandibles appear to be moved by a narrow black central tendon under the dorsal skin terminating a little beyond the base of the first segment; besides this, there are four others, two on each side of it, the outer ones diverging, much slenderer, and very short. The last or anal joint of the body very minute; exerting two short, filiform horns, or rather respiratory organs. I could discover, in this animal, no respiratory plates, such as are found in the larvæ of _Muscidæ_, _&c._ nor were the tracheæ visible. When given to me, it was alive and extremely active, writhing itself into various contortions with great agility. It moved, like other dipterous larvæ, by means of its mandibles. Upon wetting my fingers more than once, to take it up when it had fallen from a table upon which it was placed, the saline taste with which it was imbued was so powerful that it was some time before it was dissipated from my mouth.--I shall only mention one more instance, because it is a singular one. The larva of _Helophilus pendulus_, a fly peculiarly formed by nature for inhabiting fluids, has been found in the stomach of a woman[226].

You will smile when I tell you that I have met with the prescription of a famous urine-doctor, in which he recommends to his credulous patient to take a certain number of _sow bugs_ per diem, by this name distinguishing, as I suppose, the pill-millepede (_Armadillo vulgaris_), once a very favourite remedy. What effect they produced in this case I was not informed; but the learned Bonnet relates that he had seen a certificate of an English physician, dated July 1763, stating that, some time before, a young woman who had swallowed these animals alive, as is usually done, threw up a prodigious number of them of all sizes, which must have bred in her stomach[227].--Another apterous species appears to have been detected in a still more remarkable situation. Hermann, the author of the admirable _Mémoire Apterologique_, whose untimely death is so much to be lamented, informs us that an Acarus figured and described in his work (_A. marginatus_), was observed by his artist running on the _corpus callosum_ of the _brain_ of a patient in the military hospital at Strasbourg, which had been opened but a minute before and the two hemispheres and the _pia mater_ just separated. He adds that this is not the first time that insects have been found in the brain. Cornelius Gemma, in his _Cosmocritica_, p. 241, says that on dissecting the brain of a woman there were found in it abundance of vermicles and _punaises_[228].

It was customary in many countries in ancient times to punish certain malefactors by exposing them to be devoured by wild beasts: but to expose them to _insects_ for the same purpose was a refinement in cruelty, which seems to have been peculiar to the despots of Persia. We are informed that the most severe punishment amongst the Persians was that of shutting up the offender between two boats of equal size; they laid him in one of them upon his back, and covered him with the other, his hands, feet, and head being left bare. His face, which was placed full in the sun, they moistened with honey, thus inviting the flies and wasps, which tormented him no less than the swarms of maggots that were bred in his excrements and body, and devoured him to the very entrails. He was compelled to take as much food as was necessary to support life, and thus existed sometimes for several days. Plutarch informs us that Mithridates, whom Artaxerxes Longimanus condemned to this punishment, lived seventeen days in the utmost agony; and that, the uppermost boat being taken off at his death, they found his flesh all consumed, and myriads of worms gnawing his bowels[229]. Could any natural objects be made more horrible and effectual instruments of torture than _insects_ were in this most diabolical invention of tyranny?

In this enumeration of evils derived from insects, I must not wholly pass over the serious and sometimes fatal effects produced upon some persons by eating honey, or even by drinking mead. I once knew a lady upon whom these acted like poison, and have heard of instances in which death was the consequence. Sometimes, when bees extract their honey from poisonous plants, such results have not been confined to individuals of a particular habit or constitution. A remarkable proof of this is given by Dr. Barton in the fifth volume of _The American Philosophical Transactions_. In the autumn and winter of the year 1790, an extensive mortality was produced amongst those who had partaken of the honey collected in the neighbourhood of Philadelphia. The attention of the American Government was excited by the general distress, a minute inquiry into the cause of the mortality ensued, and it was satisfactorily ascertained that the honey had been chiefly extracted from the flowers of _Kalmia latifolia_.

Amongst other _direct_ injuries occasioned by these creatures, perhaps, out of regard for the ladies, I ought to notice the alarm which many of them occasion to the loveliest part of the creation. When some females retire from society to avoid a wasp; others faint at the sight of a spider; and others, again, die with terror if they hear a death-watch: these groundless apprehensions and superstitious alarms are as much real evils to those who feel them, as if they were well founded. But having already adverted to this subject, I shall here only quote the observation of a wise man, that "Fear is a betraying of the succours that reason offereth[230]." The best remedy, therefore, in such cases is going to reason for succour. In a few instances, indeed, the evil may take root in a constitutional defect, for there seems to be some foundation for the doctrine of natural antipathies: but, generally speaking, in consequence of the increased attention to Natural History, the reign of imaginary evils is ceasing amongst us, and what used to shake the stout hearts of our superstitious ancestors with anile terrors, is become a subject of interesting inquiry to their better informed descendants, even of the weaker sex.

And now, my friend, I flatter myself you feel disposed to own the truth of my position, however it might startle you at first, and will candidly acknowledge that I have proved the empire of these despised insects over man's person: and that, instead of being a race of insignificant creatures, which we may safely overlook, as having no concern with, they may, in the hands of Divine Providence, and even of man, become to us fearful instruments of evil and of punishment. I shall next endeavour to give you some idea of the _indirect_ injuries which they occasion us by attacking our property, or interfering with our pleasure or comfort--but this must be the subject of another letter.

I am, &c.

FOOTNOTES:

[106] Joel ii. 25.

[107] _On the Blight in Corn_, p. 9.

[108] Leeuw. _Epist._ 98. 1696.

[109] Bingley, _Anim. Biogr._ first edition, iii. 437. St. Pierre's _Studies_, &c. i. 312.

[110] _Hist. Animal._ l. 5. c. 31.

[111] From the terms employed by Aristotle and Dr. Mead in their Account of these cases, it appears that the animal they meant could not be maggots, but something bearing a more general resemblance to lice.

[112] _On Cutaneous Diseases_, 87, 88; and _t._ 7. _f._ 4.

[113] Latreille at first considered this as belonging to a distinct genus from the common mite (_Acarus domesticus_), which he named _Sarcoptes_; but upon its being discovered that it also has mandibles, he has suppressed it. _N. Dict. d'Hist. Nat._ xxi. 221.

[114] _On Morbid Poisons_, 306, 307.

[115] Mouffet, 267.

[116] _Medica Sacra_, 104, 105.

[117] It is to be hoped this new word may be admitted, as the _laying of eggs_ cannot otherwise be expressed without a periphrasis. For the same reason its substantive _Oviposition_ will be employed.

[118] _Mém. Apterologique_, 19.

[119] Insecta ejusmodi minutissima, forte _Acaros_ diversæ speciei causas esse diversorum morborum contagiosorum, ab analogia et experientia hactenus acquisita, facili credimus negotio. _Amœn. Ac._ v. 94.

[120] _Amœn. Ae._ v. 94-98.

[121] Mouffet, 266.

[122] Acarus sub ipsa pustula minimè quærendus est, sed longius recessit, sequendo rugam cuticulæ observatur. _Amœn. Ac._ v. 95. not. **.

[123] _Observations_, &c. 296.

[124] Extractus acu et super ungue positus, movet se si solis etiam calore adjuvetur. _ubi supr._ Ungui impositus vix movetur: si vero oris calido halitu affletur, agilis in ungue cursitat. _Fn. Suec._ 1975.

[125] Neque Syrones isti sunt de pediculorum genere, ut Johannes Langius ex Aristotele videtur asserere: nam illi extra cutem vivunt, hi vero non. _ubi supr._

[126] Imo ipsi _Acari_ præ exiguitate indivisibiles, ex cuniculis prope aquæ lacum quos foderunt in cute, acu extracti et ungue impositi, caput rubrum, et pedes quibus gradiuntur ad solem produnt. p. vi.

[127] Teredo sive exiguus vermiculus, qui subter cutim erodit agitque cuniculos in pruriginosis manibus. Gouldman tells us these _Acari_ were also called _Hand-worms_. Another English name is given in Mouffet, viz. _Wheale-worms_.

[128] _Osservazioni intorno à pellicelli del corpo umano fatte dal Dottor_ Gio Cosimo Bonomo, &c. _f._ 1-3. Baker _On Microsc._ i. _t._ 13. _f._ 2.

[129] De Geer, vii. _t._ 5. _f._ 12. 14.

[130] _Mém. Apterologique_, 79.