Explanation 
follows 
impulse. 
Chemistry 
cannot ex- 
plain all. 
Nitrogen 
compounds 
and hard 
work, 
28 ON THE PLACE OF FISH TN 
generations preceded the explanation which chemistry 
now offers of why certain things are habitually done, 
there is the well-known fact that in cold countries 
and during cold weather more fat is eaten than in 
hot, and the explanation is that fat contains so much 
Carbon, the oxidation of which produces heat. As 
heat is the basis of force in the body this is also the 
explanation of why labourers eat “hunks” of cold 
bacon and fat pork. The oxidation of the Carbon 
furnishes force for their work. 
Because the nitrogenous compounds as shown above 
contain 534 or 54 per cent. of carbon it would at first 
appear that they can furnish more heat and force than 
starch or sugar, which contain only 44 or 40 per cent. 
But it has been found that when nitrogenous matters 
are oxidized in the body a portion (about one-seventh) 
of the Carbon and Hydrogen passes away wsused. 
Deducting 8 as the nearest whole number to represent 
one-seventh of 54, we see that not more than 46 per 
cent. of the C is oxidised, which brings it down nearly 
to the value of the starches. 
This is as far as chemistry is able to offer any help 
at present, but so far, repeated experiments confirm 
what has been arrived at. Still there are some facts 
for which chemistry at present can offer no explana- 
tion. One of these affects those doing severe work. 
It is this—that severe muscular work requires an 
increase in the quantity of the nitrogenous compounds 
in food. This does not appear to be the case with the 
mere increase in the number of hours of work, it is 
the severity or as it is commonly called the “hard- 
ness” of the work that makes the difference. Though 
the scientific chemist cannot explain it, it is accepted 
