172 FISH-CULTURAL ASSOCIATION, 
Along with the analyses of food-fishes and invertebrates, a 
parallel series of analyses ofeother food materials, animal and 
vegetable, has been undertaken at the instance of the United 
States National Museum, to furnish data for illustrating its 
food collection. The results are, of course, valuable in connec- 
tion with our present subject, as we need to know not only the 
composition and nutritive value of fish, but, also, how they com- 
pare in these respects with other materials used for food. 
The report of the United States Fish Commission for 1880, 
contained accounts of some of the earlier portions of the inves- 
tigation. I hope a detailed account of the work up to the pres- 
ent may be printed soon. Meanwhile I desire to lay before the 
Fish-Cultural Association some of the more important results, 
in so far as they bear upon the nutritive values of the food-fishes 
and invertebrates that have been studied. 
Inasmuch as these statements may come under the notice of 
some who are not entirely familiar with the later results of the 
investigation of the laws of nutritive values of food materials, 
and how they are most economically utilized, a few explanations 
may be in place. These will be the more appropriate, because late 
investigation is tending to decide some disputed questions re- 
garding the ways in which food is used in the body, and because 
many of the statements which go the rounds of the papers and 
still linger even in current works on physiology and chemistry, 
are shown by the researches of a few years past to be mislead- 
ing, and in too many cases, decidedly incorrect. I may, perhaps, 
be pardoned therefore if the statements which follow contain 
some slight repetition of those made in papers previously pre- 
sented to the Association. 
THE NUTRITIVE VALUES OF FOODS. 
It is a striking fact that while the chief item of the living ex- 
penses of the majority of civilized men is the cost of their food, 
even the most intelligent know less of the actual value of their 
food than of any other of the important articles they buy. It 
makes but little difference to the man with $5,ooo per annum, 
whether he pays fifteen cents or five dollars per pound for the 
