356 



ON THE PLACE OF FISH IN 



Two impor- 

 tant groups 

 of food 

 compounds. 



Nitrogenous 

 compounds. 



ference, as to what they do in the body, between the 

 compounds which contain N, and those which do not, 

 .that this forms the ground of division into two great 

 groups. 



It is customary to speak of the C H O compounds 

 as Carbon compounds, and C H O N compounds as 

 Nitrogen compounds. It has often been found that 

 in some minds a confusion exists between the element 

 Carbon itself and carbon compounds, and the element 

 Nitrogen and nitrogen compounds. It would avoid 

 this confusion to adopt the names " C H O com- 

 pounds," and " C H O N compounds," but it would be 

 an untried innovation, and the usual custom of using 

 the names is followed. 



The important point to notice is that both groups 

 contain C and H, and the distinction of names is not 

 meant to imply that one group contains only Nitrogen 

 and the other Carbon. Both have C and H, which 

 produce heat and force, but the nitrogenous group 

 only can, so far as we know, in addition to producing 

 heat and force, form muscle. 



It will, of course, not be forgotten that though 

 muscle cannot be formed without nitrogenous com- 

 pounds, the mere fact of having a plentiful supply of 

 them in the blood will not form muscle. A muscle 

 increases only by use use, with a plentiful supply of 

 nitrogenous compounds in the blood. The importance 

 of fish diet in relation to this plentiful supply will be 

 seen from the table on p. 362. 



It is found that all the NITROGENOUS COMPOUNDS 

 used as food have very nearly the same proportions 

 of C, H and N. The elements in them are differently 

 grouped, and to the scientific chemist they present 



