1040 PEPSIN, HEMATOSIN, GLOBULIN, &C. 



pearance of solid glue. But it is not precipitated by tannic acid ; 

 on the other hand it gives precipitates with acetic acid, alum, 

 acetate of lead and protosulphate of iron, which do not disturb a 

 solution of gelatin. Chondrin leaves behind when burned above 

 4 per cent of bone earth. It appears also, like the protein com- 

 pounds, to contain a small portion of sulphur in combina- 

 tion. 



M. Scherer analysed this substance in its natural state, before 

 it is altered by boiling, operating upon the rib-cartilage of young 

 calves and the cornea. The cartilage was scraped clean by a 

 knife, then digested in water containing some nitrate of potash 

 in solution, to dissolve out albumen, and afterwards boiled in 

 alcohol and ether for the extraction of fat. Dried at 2 1 2o, it 

 left when burned 6.6 per cent of earthy ashes. The results of 

 an analysis of this chondrin and also of that of the cornea were 

 as follows : 



100.000 100.000 100.000 



From which, M. Scherer deduces the following empyrical 

 formula for chondrin, C 48 H 40 N 6 O 20 . Chondrin thus contains 

 the elements of one atom of protein, with 4 atoms of water, 

 and 2 atoms of oxygen. 



Middle coat of the arteries. This is a highly elastic mem- 

 brane, of a yellowish white colour. Purified in the same man- 

 ner as the rib cartilage, and dried at 212, it left, when burnt, 

 1.7 per cent of ashes. Its analysis gave a result considerably 

 different from that of chondrin, namely : 



i. ii. By calculation. 



Carbon. . 53.750 53.393 53.91 



Hydrogen. . 7-079 6.973 6.96 



Nitrogen. . 15.360 15.360 15.60 



Oxygen. . 23.811 24.274 23.53 



100.000 100.000 100.000 



