----This done, commended
Grace by his priest, the feast is ended.—
Having considered insects as adding to the general stock of food, I shall next request your attention while I detail to you how far the medical science is indebted to them. Had I addressed you a century ago, I could have made this an ample history. Amongst scores of infallible panaceas, I should have recommended the woodlouse as a solvent and aperient; powder of silkworm for vertigo and convulsions; millepedes against the jaundice; earwigs to strengthen the nerves; powdered scorpion for the stone and gravel; fly-water for disorders in the eyes; and the tick for erysipelas. I should have prescribed five gnats as an excellent purge; wasps as diuretics; lady-birds for the colic and measles; the cockchafer for the bite of a mad dog and the plague; and ants and their acid I should have loudly praised as incomparable against leprosy and deafness, as strengthening the memory, and giving vigour and animation to the whole bodily frame[595]. In short, I could have easily added to the miserably meager list of modern pharmacopœias, a catalogue of approved insect-remedies for every disease and evil
"that flesh is heir to!"
But these good times are long gone by. You would, I fear, laugh at my prescriptions notwithstanding the great authorities I could cite in their favour; and even doubt the efficacy of a more modern specific for tooth-ache, promulgated by a learned Italian professor[596], who assures us that a finger once imbued with the juices of Rhinobatus antiodontalgicus (a name enough to give one the tooth-ache to pronounce it) will retain its power of curing this disease for a twelvemonth! I must content myself, therefore, with expatiating on the virtues of the very few insects to which the sons of Hippocrates and Galen now deign to have recourse. At the same time I cannot help observing that their proscription of the remainder may have been too indiscriminate. Mankind are apt to run from one extreme to the other. From having ascribed too much efficacy to insect-remedies, we may now ascribe too little. Many insects emit very powerful odours, and some produce extraordinary effects upon the human frame; and it is an idea not altogether to be rejected, that they may concentrate into a smaller compass the properties and virtues of the plants upon which they feed, and thus afford medicines more powerful in operation than the plants themselves. It is at least worth while to institute a set of experiments with this view.
Medicine at the present day is indebted to an ant (Formica bispinosa, Oliv. fungosa, F.) for a kind of lint collected by that insect from the Bombax or silk cotton-tree, which as a styptic is preferable to the puff-ball, and at Cayenne is successfully used to stop the blood in the most violent hæmorrhages[597]; and gum ammoniac, according to Mr. Jackson[598], oozes out of a plant like fennel, from incisions made in the bark by a beetle with a large horn. But with these exceptions, (in which the remedy is rather collected than produced by insects,) and that of spiders' webs, which are said to have been recently administered with success in ague, the only insects which directly supply us with medicine are some species of Cantharis and Mylabris. These beetles however amply make up in efficacy for their numerical insignificance; and almost any article could be better spared from the Materia Medica than one of the former usually known under the name of Cantharides, which is not only of incalculable importance as a vesicatory, but is now administered internally in many cases with very good effect. In Europe, the only insect used with this view is the Cantharis vesicatoria; but in America the C. cinerea and vittata (which are extremely common and noxious insects, while the C. vesicatoria is sold there at sixteen dollars the pound,) have been substituted with great success, and are said to vesicate more speedily, and with less pain, at the same time that they cause no strangury[599]: and in China they have long employed the Mylabris Cichorei, which seems to have been considered the most powerful vesicatory amongst the ancients, who however appear to have been acquainted with the common Cantharis vesicatoria also, and to have made use of it, as well as of Cetonia aurata and some other insects mentioned by Pliny[600]. Another species of Mylabris has been described by Major-general Hardwicke in the Asiatic Transactions[601], plentiful in all parts of Bengal, Bahar, and Oude, which is fully as efficacious as the common Spanish fly.
But it is as supplying products valuable in the arts and manufactures, that we are chiefly indebted to insects. In adverting to them in this view, I shall not dwell upon the articles derived from a few species in particular districts, and confined to these alone, such as the soap which in some parts of Africa is manufactured from a beetle (Chlænius saponarius[602]); the oil which Molina tells us is obtained in Chili from large globular cellules found upon the wild rosemary, and supposed to be produced by a kind of gall-fly[603]; and the manure for which Scopoli informs us the hosts of Ephemeræ that annually emerge in the month of June from the Laz, a river in Carniola, are employed by the husbandmen, who think they have had a bad harvest unless every one has collected at least twenty loads[604].
Still less is it my intention to detain you in considering the purpose to which in the West Indies and South America the fire-flies are put by the natives, who employ them as lanterns in their journeys, and lamps in their houses[605];—or the use as ornaments to which some insects are ingeniously applied by the ladies, who in China embroider their dresses with the elytra and crust of a brilliant species of beetle (Buprestis vittata); in Chili and the Brazils form splendid necklaces of the golden Chrysomelidæ and brilliant diamond beetles, &c.[606]; in some parts of the continent string together for the same purpose the burnished violet-coloured thighs of Geotrupes stercorarius, &c.[607]; and in India, as I am informed by Major Moor and Captain Green, even have recourse to fire-flies, which they inclose in gauze and use as ornaments for their hair when they take their evening walks. I shall confine my details to the more important and general products which they supply to the arts, beginning with one indispensable to our present correspondence, and adverting in succession to the insects affording dyes, lac, wax, honey, and silk.
No present that insects have made to the arts is equal in utility and universal interest, comes more home to our best affections, or is the instrument of producing more valuable fruits of human wisdom and genius, than the product of the animal to which I have just alluded. You will readily conjecture I mean the fly that gives birth to the gall-nut, from which ink is made,—How infinitely are we indebted to this little creature, which at once enables us to converse with our absent friends and connexions be their distance from us ever so great, and supplies the means by which, to use the poet's language we can
"——give to airy nothing
A local habitation and a name!"