24 CHEMICAL COMPOSITION OF HUMAN BODY. 



place when blood-serum alone, without the red-corpuscles, 

 or a solution of egg-albumen, instead of defibrinated blood, 

 was treated in the same way, shewing that the fibrin re- 

 sulted from transformation of the albumen, and not of any 

 other constituent of the blood. The conversion was faci- 

 litated by a temperature of from 98 to no Fahr. : was 

 prevented by an alkaline state of the fluid, but readily 

 effected when the fluid was neutral or slightly acid ; and 

 moreover was accompanied by the evolution of sulphur, 

 phosphorus, and carbonic acid. 



A variety of fibrin, named syntonin, is obtained from 

 muscular tissue, both of the striated and organic kind. It 

 differs from ordinary fibrin in several particulars, especially 

 in being less soluble in nitrate and carbonate of potash, 

 and more soluble in dilute hydrochloric acid. 



The per-centage composition of albumen, fibrin, casein, 

 gelatin, and chondrin, is thus given by Mulder : 



Horny Matter. The substance of the horny tissues, 

 including the hair and nails (with whale-bone, hoofs, and 

 horns), consists of a protein-compound, with larger pro- 

 portions of sulphur than albumen and fibrin contain. 

 Hair contains 10 per cent, and nails 6 to 8 per cent, of 

 sulphur. 



The horny substances, to which Simon applied the name 

 of keratin, are insoluble in water, alcohol, or ether; 

 soluble in caustic alkalies, and sulphuric, nitric, and hy- 



