126 MEMOIR ON THE 



lour of paper ftained yellow with turmerick. Muriated 

 barytes produced no alteration ; but nitrated filver caufed 

 a copious white precipitate. On the afhes, which remain- 

 ed undifTolved, two drachms of nitric acid a little diluted, 

 were digefted. This mixture being filtered, was divided 

 into two equal parts. To the firft portion, pruffiate of 

 pot-alh was added, which immediately ftruck a blue co- 

 lour, and Pruffian-blue was produced. To the fecond 

 portion, lixivium of mild pot-afti was added, and a copi- 

 ous precipitate was formed. This, when colle£led and 

 dried, had the appearance of lime, and was almofl: entirely 

 foluble in diftilled water. This fluid, when filtered, and 

 oxalic acid added to it, caufed a copious white fcdiment. 

 That this precipitate was lime, was, in fome meafure, con- 

 firmed, by adding diluted fulphuric acid to it, with which 

 it formed a fubftance like felenite, or fulphate of lime. 1 

 found, that, by re-dilTolving this precipitate in fulphuric 

 acid, and precipitating it again with an alkali, and 

 treating it in the manner mentioned, it gave ftronger 

 proofs with oxalic acid of the prefence of lime. On 

 the remaining allies, which was not diiTolved by the ni- 

 tric acid, I digefted fulphuric acid a little diluted ; after 

 which it was boiled on them, notwithftanding there re- 

 mained a fixed refidue. This mixture, when filtered, 

 fliowed the prefence of lime and iron to chemical tefts. 



(;/) Three ounces of black vomit were put into a re- 

 tort, and the pneumatic apparatus being aflSxed, the 

 retort was placed in a fand-bath, which was gently heat- 

 ed, after exhaufting the air in the neck of the retort. 

 The firft meafure of air that was obtained, did not 

 appear to burn when a lighted taper was prefented to 

 it. The fecond meafure of air was incorporated with 

 water, and fome iron-filings inferted in the phial, which 

 was fuffercd to remain for 24. hours. This mixture 



was 



