DIRECT BENEFITS DERIVED FROM INSECTS. 215 



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 (^Chlanius saponarius^ \) 

 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^; and the manure for which Scopoli informs us the hosts 

 of Ephemerce 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.^ 



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'* ; — 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 Chrysomelldce and bril- 

 liant diamond beetles, &ic.^ ; in some parts of the Continent string together 

 for the same purpose the burnished violet-colored thighs of Geutrupes 

 stercorarius, hc.^ ; and in India, as I am informed by Major Moor and 

 Captain Green, even have recourse to fire-flies, which they enclose 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 pro- 

 ducts 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 instru- 

 ment 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 connections be 

 their distance from us ever so great, and supplies the means by which, to 

 use the poet's language, we can 



^ive to airy nothing 



A local habitation and a name !" 



Panz., which is very abundant in the south of Europe, and is sometimes found in Germany. 

 The active blistering principle in all these insects has been detected by M. Robiquet, and 

 named by him Cantharidine, which has been ascertained by M. Bretonneau, and especially 

 by M. Leclerc, who has examined a great number of insects with this view, to be found 

 amongst coleopterous insects of the family of Cantharidce only, though not in all the species 

 of this family, nor even in all the species of the same genus. M. Leclerc, who conceives 

 that cantharidine is secreted by a peculiar apparatus, states, that it is not destroyed either 

 by the action of the air or of time ; and as it must exist in a spider of the United States 

 {Tegenaria medicinalis Hentz ; Journ. Acad. Nat. Sci. of Philadelphia, 1821, p. 53. pi. 5.), 

 which is there extensively employed as a vesicatory, he examined if this principle is to be 

 found in the Tegtnaria of France or in other spiders, but without success. (Leclerc, Essai 

 sur les Epipastiques, Paris, 1835, quoted in Guerin, Bulletin Zoologique, i. 95.) 

 ' Carahus Oliv., Entom. iii. 69. t. iii. f. 26. Compare Philanthropist, ii. 210. 



* Molina's Chili, i. 174. * Ent. Carniol. 264. 



* Captain Green was accustomed to put a fire-fly under the glass of his watch, when he 

 had occasion to rise very early for a march, which enabled him, without difficulty, to dis- 

 tinguish the hour. .. * Molina, i. 171. 285. ^ Latr. Hist. Nat. x. 143. 



