154 MANURE. 



This compound is the basis of the animal solids, 

 and soft parts : fibrin or flesh, and albumen, are only 

 a compound of this with sulphur. All the parts of the 

 animal frame are modifications only of protein. 



The peculiar principle of glue, or size, or jelly, 

 called gelatin, never exists in the healthy animal 

 body. It is the product of catalysis. Boiling water 

 is the catalytic agent, and produces it from tendon, 

 ligament, cartilage, skin and bone. The composition 

 of these, will show at once their relation to protein. 



Horny matter is equally allied to protein. Its sev- 

 eral varieties have been divided into two classes : 

 1st, soft, and 2d, compact. The first includes skin, 

 or the outer part, called cuticle ; and the delicate 

 lining membrane of the internal passages, and sacs ; 

 and these substances are like constituted. The cu- 

 ticle of the sole of the foot is composed of 



Carbon, 50-S94 



Hydrogen, 6*781 



Nitrogen, 17-225 



° x /f n ' I 25-099 



Sulphur, J 



100- (Scherer.) 



