CHONDRIN. 



from its solution. The precipitate is insoluble in water, whether 

 cold or hot ; but an excess of alum or sulphate of alumina im- 

 mediately dissolves it. Hence, to precipitate chondrin completely 

 by these reagents, we must add them cautiously, and drop by 

 drop, to avoid any excess. The filtered liquor will not gelatinize, 

 and contains very little animal matter. 



The precipitate by alum or sulphate of alumina is not redis- 

 solved by the addition of a little acetate of potash or of soda, or 

 of common salt ; but if a great quantity of these salts be added, 

 the precipitate is redissolved. 



The precipitate by acetate of lead is not redissolved by an ex- 

 cess of the reagent. The precipitate by persulphate of iron is 

 abundant and bulky. It is not redissolved by an excess of the 

 reagent unless we apply heat, in which case solution takes place. 



4. If to a solution of chondrin we add muriatic acid in very 

 minute quantity, not more than a fraction of a drop, the chondrin 

 is precipitated. A greater quantity of the acid not only does 

 not precipitate but redissolves what may have at first fallen. 

 Muriate of chondrin, (if we can give that name to a mixture of 

 solution of chondrin and muriatic acid,) is not precipitated by 

 prussiate of potash. 



5. A very concentrated solution of chondrin is not precipi- 

 tated by caustic alkaline ley. But this ley precipitates collin ; 

 and the precipitate contains a great deal of phosphate of lime. 



6. Chondrin is precipitated by chloride of platinum, but not 

 by nitrate of silver. 



7. Alcohol throws down chondrin from a concentrated solu- 

 tion in white, consistent, thready flocks. If we filter off the al- 

 cohol the chondrin remains translucent and does not seem alter- 

 ed in its properties. For it dissolves in hot water and gelatinizes 

 as before. In this respect chondrin agrees with collin. 



The alcohol will be found to have dissolved a small quantity 

 of a substance which is not chondrin. For it dissolves in cold 

 water, does not gelatinize, and is precipitated by tannin. These 

 are the . characters assigned to the principle distinguished by 

 Thenard by the name of osmazome, about which we at present 

 know very little. 



8. The only known animal substance precipitated by acetic 

 acid besides chondrin is casein. But the two cannot easily be 

 confounded together. Casein does not gelatinize. Its acid so- 



