Art ON THE YOLK OF WOOL. 



matter, of a grey colour, with which the acids produce a pretty 



brifk efTervefcence, which fliows the prefence of an alkaline 



Contains an al- carbonate. The portion which retains its fokibility in water 



kaJinecarboiiatc.^^^j^^j^j^^f^g a reddidi colour and a faline tafte to this fluid; 



its folution is not dlflurbed by the acids, as it was before having 



been treated by alcohol. CauIUc alkalis do not difengage any 



A<Sion of ic- ammonia; the muriate of barites forms a very abundant depo- 



agents. fition in it, the greateft part of which is foluble in water: the 



nitrate of filver alfo occafions a precipitate in it, which ditTolves 



partly in nitric acid. Alcohol precipitates this matter in the 



form of a mucilage, which is depofited quickly. 



Nitrate of iron being mixed with the folution of this fub- 

 ftance, formed a brown precipitate in it, and at the end of 

 fome days, the liquor furnifhed a pretty large quantity of ni- 

 trate of potafh. 



The yolk being decompofed by dilute fulphuric acid, and 

 the liquor filtered, it blackened by evaporation, exhaled va- 

 pours of fulphuric acid, and became carbonaceous, as the con- 

 centration of the fulphuric acid took place. The refidue being 

 afterwards wathed with water, and the folution fuitably eva- 

 porated, yielded cryftals of neutral fulphate of potafh, but a 

 good deal remained in the folution on account of the fuper- 

 abundant acid which brought it to the ftate of an acidulous 

 fait: by a longer evaporation, this fait crj'flallizes in needles 

 and plates of a pearly white. 

 Yields fulphate During the courfeof thefe fucceffive evaporations, another 



of lime by fuU f -^^^ ^f ^^^ ^.^^ oflered, in the form of flattened needles, of ' 

 pnuric acHi j ' . . , 



a fattiny white, and without any fenfible tafte. 



This fait examined with care, appeared (o me to be only ful- 

 phate of lime; it however differed from it in fome refpe6^s; 

 for example, it melts much more readily by the flame of the 

 blow-pipe into a globule, tranfparent while it is in fufion, and 

 which becomes opaque by contrading : it is alfo much more 

 foluble in water, and neverthelefs does not contain the acid in 

 excefs; as I have fatisfied myfelf. Its folution in water pre- 

 cipitates muriate of barites and oxalate of ammonia abundantly : 

 one of thefe precipitates is fulphate of barites, and the other 

 oxalate of lime. Neither lime-water nor ammonia difturb its 

 folution. It appears therefore that this fait is a modification of 

 fulphate of lime, which is probably produced by the proportion 

 of its elements. It may alfo be poflible that this fait ftill con- 

 S tains 



