Report on the Memoirs, &c. 53 



This system answers to a division of the octave in- 

 to 55 equal paits, and according to tii<- papers of 

 M» Sauveur in Hit Memoirs of the Paris; a.:. Academy, 

 for 1707 and !7 11, W vvas the system used by m 

 Musicians of Paris at or previous to that time. See 

 his general table of tempered systems above referred to. 

 I am, sir, 



Your obedient humble servant, 



Westminster, July 11, 1810. J. FAREY. 



VII. Report on the Memoirs presented to the Society of 

 Pharmacy at Paris, in consequence of the Prizes offered 

 in the Year 1809. Extracted by 37. Bouillon La- 

 grange from the full Report drawn up by Messrs. 

 Nachet, Dejiosne, and Vallee. 



KJj nine memoirs sent to the Society, two have particu- 

 larly fixed the attention of the committee. They were 

 written in answer to the following question : 



44 To prepare the acetate of potash, so as to obtain it white 

 and saturated, without employing radical vinegar, and 

 without having recourse to fusion ; — to point out which of 

 the two, the acid or the alkali, gives it the colouring prin- 

 ciple. " 



The first memoir, with the motto Ex cognitis incognita, 

 is written with great precision. 



The author, alter having ascertained the advantage which 

 would result from obtaining this salt in all its purity by a 

 simple and (Economical process, begins by inquiring from 

 whence the colouring principle arises : It cannot, he says, 

 be owing* to the alkali, when it is considered that the fusion 

 of the acetate of potash renders it insoluble, and that the 

 heat requisite for this fusion is not so strong as that which 

 is necessary tor the preparation of anv given potash; and 

 on the other hand, it cannot be essentia! to the acetic acid, 

 when radical vinegar is capable of instantly furnishing a 

 colourless salt. Consequently, this colouring principle 

 must be a foreign substance contained in common vinegar, 

 and which may be introduced into it it) distillation. But 

 this same principle is less volatile than the acetic acid, 

 since distilled vinegar leaves a residue of it if we evaporate 

 it a second time : it is not very soluble by itself, and it 

 cannot be dissolved except by the addition of acetic acid, 

 since it is precipitated, at least in part, when we saturate the 

 latter bv potash: and iinallv, it has been ascertained that 



D 3 it 



