183 
mals experimented upon had to be weighed to a fraction, sub- 
jected to conditions maintained with the utmost uniformity, fed 
and watered with scientific accuracy as to the amount as well as 
the kind of food and drink, and the effects noted at intervals by 
fresh weighings and careful determinations of the animals’ condi- 
tion. Asa result of these observations, a set of new tables of 
the nutritive ratio and feeding value of foods was established, 
and the results registered under the term ‘‘ Digestible nutrients ”’ 
instead of merely ‘‘ Nutrients,”’ as before. This branch of inves- 
tigation was developed chiefly by Mr. John Lawes, of England, 
and his labors were so highly appreciated that he was knighted 
in recognition thereof. It is now to be noted, in all comparative 
tables, that the zutrients and the digestible nutrients of a given 
food are often at wide variance one with another. Not only 
have the different foods been contrasted in this new direction, 
but the value of the same food has been carefully compared 
under different conditions, as to the age of the plant, flowering, 
or fruiting, soil, climate and other circumstances. 
It is to be observed that the injurious effects upon the nutritive 
values of foods resulting from the changes described above are of 
an indirect character only. That is, they do not impart to the 
foods any harmful properties, but serve merely to interfere with 
or reduce their usefulness. <A totally different class of effects, 
imparting properties distinctly injurious, or at least objectionable 
to the animal system, depend upon provisions made by the 
plants for protecting their nutrients against decomposition or 
against consumption by animals. It is ever to be borne in mind 
that vegetable nutrients are substances manufactured by the 
plant, at a great expenditure of vital energy, for its own con- 
sumption or for that of its progeny. Even those which are 
classed as “for immediate consumption’? must persist for a 
longer or shorter period; and by far the greater portion of those 
available for use by man belong to the “ reserved storage’’ class 
and are intended to be preserved for the plant’s own use for one 
or more years. This long duration involves dangers of various 
kinds. Decay, resulting from the attacks of germs of various 
classes, is prevented by the manufacture and storage with the 
