40 PROTEINE. [CHAP. I. 



and any salts which may be mixed with it, and to set the proteine 

 free. 



Proteine, when dried, forms a hard, brownish-yellow substance, 

 without taste, and insoluble in water and alcohol. It attracts 

 moisture from the air, and swells out again into a gelatinous mass 

 when moistened. It is soluble in all acids, when diluted; and 

 forms combinations with them, which are with difficulty, or not at 

 all, soluble in excess of acid. It is also dissolved in dilute alkalies, 

 or in solutions of alkaline earths. 



The ultimate analysis of proteine, according to Mulder, from one 

 hundred parts gives as follows : 



Nitrogen .... 16-01 



Carbon .... 55-29 



Hydrogen .... 7-00 



Oxygen .... 21-70 



100-00 



* 



The following table exhibits the relations which albumen, fibrine, 

 and caseine bear respectively to proteine : 



Albumen of Serum = 10 eqts. Proteine -f 1 eqt. Phosph. + 2 eqts. Sulph. 

 Albumen of Egg = 10 eqts. Proteine + 1 eqt. Phosph. + 1 eqt. Sulph. 

 Fibrine = 10 eqts. Proteine -j- 1 eqt. Phosph. + 1 eqt. Sulph. 



Caseine =10 eqts. Proteine + 1 eqt. Sulph. 



Besides the essential elements of these proximate principles, which 

 are obtained by their ultimate analysis, we find certain salts mixed 

 with them. In albumen, phosphates and sulphates of earths and 

 alkalies and chloride of sodium; in fibrine, phosphate of lime; 

 and in caseine, the same salt, in the proportion of 6*24 per cent. 

 As the phosphate of lime is the same as bone-earth, the existence 

 of it in union with the proximate principle, which forms the chief 

 constituent of milk, seems to have reference to the process of 

 ossification during the growth of the infant. 



Proteine, in every respect the same as that which forms the 

 basis of the proximate principles just described, may be obtained 

 from similar elements in the vegetable kingdom. Gluten, which 

 exists abundantly in the seeds of the Cerealia, yields a principle 

 which is called vegetable fibrine ; the same substance coagulates 

 spontaneously in the newly expressed juice of vegetables. From 

 the clarified juices of cauliflower, asparagus, mangel-wurzel, or 

 turnips, when made to boil, a coagulum is formed, which cannot be 

 distinguished from the coagulated albumen of serum or the egg. This 



