ift;8 I'tfe of Defatijfure, 



This golden, yellow, detonating, and cryftallizable fubftajice, is called the bitter principle 

 by the author. Its cryftals appear to be oiStahedrons. 



As animal fubftances become yellow by the conta(Sl of nitrous acid, citizen Welter en- 

 deavoured to extraft the latter principle from beef; but he found it combined with another 

 fubftance likewife unchangeable by the nitric acid. This combination, which is foluble 

 'n the concentrated nitric acid, is feparated by water in the form of a yellow powder, which 

 does not change by expofure to the air, and may probably be ufeful in painting. 



Cit, Welter was induced to fuppofe, that this powder is compofed of the bitter principle, 

 and another fubftance, from the circumflance of his having obtained the latter fubftance by 

 treating fponge with the nitric acid. It is colourlefs, foluble in the concentrated nitric acid, 

 and precipitable by water like the other powder. 



Thefe fa<fts feem to (how, that animal matters treated with the nitric acid, afford two 

 fubftances as a refidue, which are not changed by this acid, and are found eitiier in a com- 

 bined or feparate ftate. It appears that filk affords the bittet principle in a ftate of purity. 

 Sponge affords the fecond fubftance pure; and beef affords a combination of both. The 

 bitter principle is yellow and foluble in water ; the combination of both is alfo infoluble ir> 

 water, but coloured- 



Cit. Welter remarks, that having made his experiment only once, and not being able 

 yet to determine with precifion the circumftances upon which the production of the bitter 

 principle depends, he has thought it neceffary to relate the whole. 



w '.-.■. . * . . . ' im 



XII. 



AJhort Account of the Life anS PfYitings of Defauffure. By A. P. DzCANDOLE. * 



He 



-OR ACE Benedia Defauffure was bornat Geneva in the year 1 740; his father, an enlight- 

 ened cultivator, to whom the public is indebted for fome memoirs concerning rural economy, 

 refided at Conches, a country-houfe fituated on the banks of the river Arve, half a league from 

 Geneva. This habitual refidence in the country, together with anadive education, was un- 

 doubtedly the caufe which developed in Defauffure that natural ftrength of conftitution fo ne- 

 ceffary to the practical cultivator of natural hiftory. He went every day to the town, in 

 Arder to profit by the advantage of public education. Redding at the foot of the Saleve, a 

 mountain he has fmce rendered famous by his refearches, it was an entertainment to him to 

 climb its rugged paths. Living thus furrounded by the phenomena of nature, and poffeffing 

 the advantage of ftudy, he became atuched to natural hiftory, without imitating thofe 

 learned men who form theories without leaving their cabinets, nor thofe men of mere prac- 

 tice, who being continually furrounded by natural fcenes, become incapable of admiring their 

 i)eauty. 



• Decade Philof. Anvii. 327. 



