FIBRINE AND ALBUMEN. 43 



is destitute of nitrogen ; all of them contain likewise 

 carbon and the elements of water, the latter, 

 however, in no case in the proportion to form 

 water. 



The chief ingredients of the blood contain nearly 

 17 per cent, of nitrogen, and no part of an organ 

 contains less than 17 per cent, of nitrogen. (7) 



The most convincing experiments and observa- 

 tions have proved that the animal body is absolutely 

 incapable of producing an elementary body, such as 

 carbon or nitrogen, out of substances which do not 

 contain it ; and it obviously follows, that all kinds 

 of food fit for the production either of blood, or of 

 cellular tissue, membranes, skin, hair, muscular fibre, 

 &c., must contain a certain amount of nitrogen, 

 because that element is essential to the composition 

 of the above-named organs ; because the organs can- 

 not create it from the other elements presented to 

 them ; and, finally, because no nitrogen is absorbed 

 from the atmosphere in the vital process. 



The substance of the brain and nerves contains a 

 large quantity of albumen, and, in addition to this, 

 two peculiar fatty acids, distinguished from other fats 

 by containing phosphorus (phosphoric acid ?). One of 

 these contains nitrogen (Fremy). 



Finally, water and common fat are those ingre- 

 dients of the body which are destitute of nitrogen. 

 Both are amorphous or unorganised, and only so far 

 take part in the vital process as that their presence 

 is required for the due performance of the vital 



