ChemicO'Physiological Researches. 415 



of young calves, and the cornea. They were digested with 

 water and some saltpetre to dissolve out all albuminous ma- 

 terial, and then boiled with alcohol and aether to remove the 

 fat. 



This chondrin dried at 212° contained 6'6 per cent, of 

 ashes. 



Analysed by the usual methods the results were — 



Ribs, Cornea. 



T. II. III. 



Carbon 49*496 50-895 49*522 



Hydrogen 7'] 33 6*962 7*097 



Nitrogen 14*908 14*908 14*399 



Oxygen 28*463 27*235 28*982 



100*000 100*000 100-000 



If we take the cai'bon here as being of the same magnitude 

 as that of protein, the formula resulting from these analyses 

 is C48 H40 Ng Ogo, which differs from protein by containing 

 4 . H O and 2 . O in excess. 



The Elastic Coat of the Arteries. 

 This tissue, purified in the same manner as the other sub- 

 stances analysed, and dried at 212°, gave 1*7 per cent, of 

 ashes. 

 The analysis of it yielded — 



I. II. 



Carbon 53*750 53*393 



Hydrogen 7*079 6*973 



Nitrogen 15*360 15*360 



Oxygen 23*811 24*274 



100*000 100*000 



The formula given by these results is C48 Hgg Ng 0,g, and 

 deducting thence that of protein, C4g Hgg Ng O14, it appears 

 that the elastic coat of arteries diffei's from protein in contain- 

 ing plus the elements of two atoms of water. 



Corneous Tissues. 



This substance presents itself in two forms, memlranous 

 and compact. The first constitutes the epidermis and the 

 epithelium in its various forms; the latter constitutes hair, 

 horns, nails, &c. 



A. Membranous Corneous Tissue. — For analysis. Dr. Scherer 

 selected the epidermis of the sole of the foot where it is thick- 

 est and most easily separated. It was purified by boiling in 

 water, alcohol and aether. Dried at 212°, it gave 1*0 per cent, 

 of ashes. 



It was analysed as usual, except that the nitrogen was de- 

 termined directly by volume in the old manner. 



