On the Virtues and Principles of Caniharides, 145 



nagement of the flock to Sir Joseph Banks, all letters on 

 the subject of it, addressed to him in Soho-squarc, will be 

 answered, aiid the utmost endeavours used to consult the 

 convenience of those who wish to become purchasers. 

 July 1802. Joseph Banks. 



XXIT. Medico-chemical Researches on the Fir lues and 

 Principles of Cantharides : extracted from a Memoir of 

 C. Beaupoil ly C. Deveux*. 



-I HOUGH the animal kingdom affords only a small number 

 of substances which can be employed in medicine, it must 

 still be allowed that among those to which it has recourse, 

 there are some the effect of u'hich is so certain, so constant, 

 and so striking, that if they were wanting it would be im- 

 possible to find others to supply their places. 



Cantharides in particular are of this number. Every 

 body knows the manner in which they act, and the re- 

 sources they afford in a variety of diseases. It needs there- 

 fore excite no surprise, that an examination of these insects 

 should at all times have engaged the attention of the most 

 celebrated physicians, and that chemists have often tried to 

 subject them to analysis. 



The principal object of all those who have laboured on 

 cantharides has been to discover whether the vesicant pro- 

 perty, which they possess in the highest degree, belongs in 

 general to all the parts of the animal, or whether it does 

 not rather reside in a particular matter, which, independ- 

 ently of those that accompany it, can act alone, and give 

 rise to the effects produced by the whole cantharides. 



It would no doubt be superfluous to relate here every 

 thing w hich has been done or said on this subject ; but it 

 is of importance to remark, that no one before Thouvenel 

 pursued the route v\'hlch would lead to a solution of the 

 proposed problem : it has been 'therefore since the period 

 when that physician pubhshed the different experiments he 

 made on cantharides, that any hopes have existed of obtain- 

 ing more accurate knowledge respecting the properties of 

 the immediate materials of these insects. 



However, in rendering justice to the efforts made by 

 Thouvenel, it must be allowed also that he has not carried 

 to a sufficient length the labour which he conunenccd so 



o 

 * From the Annntis cle Chi mi e, No lij-s. 



Vol. XVIIT. No. 70. K well, 



