6 NOTE ON THE SILKWORM. 



improved, but none of them were attacked by those diseases which had 

 caused such havoc among them in preceding years. Those worms, on 

 the contrary, though of similar origin and placed in the same locality, 

 but which were in houses built of non-injected wood, were attacked by 

 the ordinary diseases, and gave results far inferior to those which had 

 been otherwise treated. It is, therefore, clear that an advantageous anti- 

 septic result was produced by the employment of the sulphate of copper 

 as a wood-injection ; and this idea is worthy of the notice of all those 

 who are interested in the care of these worms, which are now assuming 

 an importance which they never had so extensively before. 



With regard to the diseases of the silkworm in France, it is satisfac- 

 tory to know that they are now considerably on the decline. In a com- 

 munication to the Academie des Sciences, by M. Guerin-Meneville, on the 

 25th of June, that indefatigable investigator remarked, that the cha- 

 racter of the epidemic which had previously attacked the silkworms had 

 become considerably modified — a sign that it had entered upon its 

 period of decline. Referring to his previous labours in this department, 

 and particularly those of 1849 and 1853, M. Guerin-Meneville maintains 

 his previous opinion, that the cause of the first epidemic among the 

 silkworms originated in a diseased state of the mulberry trees. This 

 explanation agrees better with the great mass of facts which have been 

 observed in the cultivation of the mulberry tree on a large scale ; for 

 others besides M. Guerin-Meneville had remarked the various phases of 

 disease which the mulberry trees assumed, being sometimes numerous 

 spots ; at other times, the falling off of the fruit before it had reached a 

 period of maturity, whilst the leaves could not be preserved in the usual 

 manner without fading away and rapidly fermenting. M. Moglia de 

 Orsinovi, who distilled the mulberry for the purpose of obtaining an 

 alcohol, lately communicated to his friends a fact no less conclusive than 

 characteristic, that of late years the mulberry fruit, instead of yielding 

 him an alcohol as usual, only gave him after distillation a species of 

 aromatic oil. On this point M. Gu6rin-Meneville observes : 



" This circumstance recalled to me at once that in my communica- 

 tions in the year 1849 on the changes in the blood of diseased silkworms, 

 I had drawn attention to the vibrating Corpuscles and the crystals as the 

 principal characteristics of the disease, and that these discoveries had been 

 the starting-point of more recent observers in the same field, whose obser- 

 vations had been considered as new. A scientific man, whilst discovering 

 my already -discovered hema tozoa, to which he simply gave another name, 

 concluded, as I had previously done, that the silkworm disease was the 

 result of some essential alteration in nutrition ; but, instead of admitting 

 with me, as was most natural in such a case, that such alteration in 

 nutrition had its cause in a vitiated nourishment supplied to the worms, 

 this party endeavoured to discover something extremely vague, which 

 he no doubt considered more scientific, remarking that this essential 



