215 

 ON THE DISEASES OF SILKWORMS. 



COMMUNICATED BT C. B. BEEE, ESQ. 



At the Meeting of the "Academie des Sciences de Paris," of June 7th., a 

 very interesting and important paper was read by M. Guerin-Meneville, en- 

 titled "New Observations on the Chemical Characters of the Diseases of 

 Silkworms." The paper is the result of thirty-eight experiments instituted 

 during the last five or six years, and its contents are extracted from M. G-. 

 Meneville's Journal, "D' Observations a Sainte-Tulle." 



These investigations are especially interesting to the manufacturing interests 

 of .France. In this country we buy and sell and wear our silk — we hear with 

 wonder of a dealer in the commodity leaving at his death a fortune of four 

 millions of pounds; but I am afraid we do not pass many thoughts upon, or 

 institute many investigations into the diseases or economy of the caterpillar, 

 by which all this beauty, usefulness, and riches is produced. But qui facit 

 per alium facit per se; and as all our Entomologists are interested in the 

 well-doing of their larvae, I shall make no apology for giving an abstract of 

 this paper; and I may take the opportunity of remarking that I hope from 

 time to time to give my readers a resume of the most interesting papers 

 on Entomology, published in the "Revue et Magazin de Zoologie," which 

 is undoubtedly one of the best and most useful Natural History periodicals 

 in Europe. 



"In modern days," remarks M. Guerin-Meneville, "all the diseases of 

 Silkworms are confounded with the epidemic, which has received the name 

 of Gattine. Nobody talks of anything else. The Muscardine even is nearly 

 forgotten, and it thus happens in regard to this disease as to great epi- 

 demics affecting the human species, such, for instance, as Asiatic Cholera. 



Having with great trouble procured three or four Silkworms, dead or 

 dying of Muscardine, I found that their blood was intensely acid; litmus 

 paper being turned red immediately by it. This redness was removed and 

 the natural colour restored by immersion into the blood of those affected 

 by Gattine. The experiment repeated many times during the last few 

 years, always with the same result, demonstrated the acid condition of the 

 blood in the one disease, and its alkaline condition in the other. I have 

 since satisfied myself by many experiments that the blood of Silkworms, 

 affected with the various maladies — Passis, Arpians, Luzettes, Vache, Flats, 

 etc., is always very decidedly alkaline. 



As a result of my experience, I class the diseases of Silkworms under 

 two divisions. 1. — Those resulting from an excess of alkaline matter, which 

 always terminates in a putrid softening. 2. — Those resulting from an excess 

 of acidity, (Muscardine and its varieties,) which end in the hardening of 

 the Silkworm, and the development of a fungus growth, (the Botrytis.) 



It has further resulted from my experience and a great number of 

 observations made in the laboratory and in the cultivated grounds, that the 

 employment of acids is indicated when the worms are attacked by the 

 alkaline disease; that this excess of alkalies proves a general feebleness in 



