CONSTITUENTS OF BLOOD. 39 



The second principal ingredient of the blood is con- 

 tained in the serum, and gives to this liquid all the 

 properties of the white of eggs, with which it is identi- 

 cal. When heated, it coagulates into a white elastic 

 mass, and the coagulating substance is called albumen. 



Fibrine and albumen, the chief ingredients of blood, 

 contain, in all, seven chemical elements, among which 

 nitrogen, phosphorus, and sulphur are found. They 

 contain also the earth of bones. The serum retains in 

 solution sea salt and other salts of potash and soda, in 

 which the acids are carbonic, phosphoric, and sulphuric 

 acids. The globules of the blood contain fibrine and 

 albumen, along with a red coloring matter, in which 

 iron is a constant element. Besides these, the blood 

 contains certain fatty bodies in small quantity, which 

 differ from ordinary fats in several of their properties. 



Chemical analysis has led to the remarkable result, 

 that fibrine and albumen contain the same organic ele- 

 ments united in the same proportion, so that two analy- 

 ses, the one of fibrine and the other of albumen, do 

 not differ more than two analyses of fibrine or two of 

 albumen respectively do, in the composition of 100 

 parts. . 



In these two ingredients of blood the particles are 

 arranged in a different order, as is shown by the dif- 

 ference of their external properties ; but in chemical 

 composition, in the ultimate proportion of the organic 

 elements, they are identical. 



This conclusion has lately been beautifully confirmed 

 by a distinguished physiologist (Denis), who has sue- 



