6 
COLORADO EXPERIMENT STATION 
was necessary to do the work of fitting them for assimilation by the 
system. Their similarity in quantity and coefficients of digestibility 
is considered fortunate as practically eliminating the question of their 
influence, the difiference of the effects of these food elements not being 
great enough to materially change the effects of the other elements 
in consideration. 
§ 12. The carbohydrates are not divided into classes except 
to the extent and in the manner explained in the following: 
The familiar members of this class, glucose and cane 
sugar, do not occur in large quantities in ordinary hays, but they are 
wholly digestible and where present constitute a valuable factor in 
the fodder. , The saltbush contains more of these two sugars taken 
together than the alfalfa does, so if we consider the value of the 
saltbush as depending on the quantity of these two substances alone 
it should be better than the alfalfa, but this is not the case. The same 
is true in regard to two others of these carbohydrates, the gums 
and starch which are more abundant in the saltbush than in the 
alfalfa. The frame work and tissues of the plants themselves very 
largely belong to this class of substances, carbohydrates, and though 
we do not know the definite composition of some of these plant con¬ 
stituents, they can be changed, in part at least, so as to yield com¬ 
pounds whose composition is known and the yield of such compounds 
by the different hays when treated with different agents has been 
made use of to establish the differences in the fodders themselves. 
The sugars already named are only two well-known members ’of this 
class of substances which include a number of others not so commonly 
known to the general public. Some of these related substances yield 
one and some another sugar under the action of certain agents. By 
taking advantage of these properties, the following differences between 
the alfalfa and the saltbush have been established. 
§ 13. It should be kept in mind that the object had in view 
in doing this work, was not primarily to establish the value of the 
fodders but to find out, if possible, why one gives goods results and 
the other poor ones. There is a kind of sugar to which the name 
wood-sugar has been given because it is formed when wood is sub¬ 
jected to a certain treatment. The sugar or the material from which 
it can be made, is capable of being determined with approximate 
accuracy by methods which have been worked out. In this way, it 
is shown that certain carbohydrates are present in that portion of the 
alfalfa soluble in alcohol which are wholly absent from the saltbush 
and these substances in the alfalfa are easilv digestible. A similar 
carbohydrate is present in the muriatic acid extract of the alfalfa. 
There is, however, twice as much of this substance in the correspond¬ 
ing extract of the saltbush, but that found in the alfalfa is wholly 
digestible, while that in the saltbush is wholly indigestible; 
this may simply mean that but little of this portion of the 
hay is changed while passing through the alimentary tract and fecal 
matter capable of yielding this substance is present in the dung in 
such large quantities that there is more in the feces than was taken 
