a^o French National Injl'itute,. 



azot. Were his ideas confirmed, we (linuld not only ap- 

 proach near to the do6lrine of the antients relfte<£ling the 

 elements, but have an eafy explanation of a multitude of 

 phenomena difficult to be accounted for in the hiftory of 

 nature; as, the faltnefs of the water of the fea; the forma- 

 tion of nitre and marine fait in inhabited places; that of 

 potafi; in vegetables, of foda in animals; the converfion of 

 fonv: of the earths into each other, &c. All thcfe fs^tls, fa 

 myiterious hi appearance, and which have exercifed the in- 

 genuity of the philofophers for fo many ages, would becon- 

 fequences eafy to be deduced from thefe principles. Unfor- 

 tunately, however, thefe chemifts have not confirmed their 

 analyfes i^y fynthefis ; that is to fay, they have not yet re-, 

 made potafli by combining diretily lime and hydrogen. 



The labour of Berthollet on the muriatic' acid had been 

 precede<l and occafiftned by another on an objcft no lefs 

 iniporlant — eud'iomctry. This is the name given to the art 

 . (i\ analyfing atmofpheric air, and in particular of aicertain- 

 ing how many parts of pure vital air or oxygen the atmo-i 

 fphcre of any place contains. The health of mankind as well 

 as philofophy is intcrefted in the perfcAion of this art. 

 The combuftion of phofphorus has been long employed for 

 this aualyfis, becaufc this combuftion abforbs the oxygen in 

 a concrete acid, and it is then eafy to meafure what rcmaias 

 under a gaftous form, which is azot. 



Mr. Irlumboldt, a learned German philofophcr, thought 

 he found this method dcfeftive, becaufc, according to his 

 accQimt, there always remained oxygen not fixed, and be- 

 caufe a portion of azot mixed itfeit with the acid. He en- 

 tertained the like opinion of liver of fulphur, or alkaline 

 hydrogenaled fulnhuret, which fome employ alfo for the 

 fame ufe, and prefers the means pointed out by Fontana, 

 or nitrous gas, which i? an aeriform combination of azot, 

 with lefs oxygen than is neceffary to form nitric acid. When 

 this gas is mixeil with new oxygen, it abforbs it more 

 exactly, according to Mr. Humbolt, than the above fub-. 

 ftances ; but as it may contain a variable quantity of azot, 

 this mean is not unattended with inconveniences. Mr„ 

 Humboldt thinks that this might be remedied by examining 

 9 each 



