THE CHEMICAL COMPOSITION OF AMERICAN GRASSES. 
In submitting grasses to chemical analysis, with a view of judging of 
their nutritive value, it is usual to determine the amount present of 
water, ash, fat or oil, fiber, and nitrogen. Irom the latter the amount of. 
albuminoids to which it is equivalent is readily calculated by multiply- 
ing by a factor which represents the per cent. of nitrogen present in the 
average albuminoid, and by substracttg the sum of all these constitu- 
ents from one hundred, the percentage of undetermined matter is ob- 
tained, and as it of course contains no nitrogen, and consists of the ex- 
tractive principles of the plant, itis described as “ Nitrogen free extract.” | 
{t ineludes all the varbo-hydrates, such as sugar, starch, and gum, to- 
gether with certain other allied substances, with which we are less in- 
timately acquainted, but which have a certain nutritive value. 
Although it has been customary to state,as albuminoids the equiva- 
lent of the nitrogen found, this is rarely entirely correct, as a portion is 
generally present in a less highly elaborated form of a smaller nutritive 
value. This portion is described as non-albuminoid nitrogen, and in 
analyses of the present day the amount is always given as an additional 
source of information, although our knowledge of its exact value to the 
animal is rather uncertain. © 
The ultimate composition of the ash is also frequently determined, 
and examples of the results obtained are of interest as showing the min- 
eral matter that grasses withdraw from the soil. 
Without entering into a discussion of the nutritive value of the several 
constituents of the grasses, for which reference can be made to Armsby’s 
Manual of Cattle Feeding, it is sufficient to say that during the past few 
years the greater portion of the species described by Dr. Vasey in the 
preceding portion of this Bulletin have been analyzed, and the results 
collected and re-arranged, with some corrections, from the annual reports 
of the Department are presented in the following pages. 
The first series consists of analyses made with specimens collected at 
or near the time of blooming. Their origin is as follows: 
No. of anal. 
1. Paspalum leve (Water Grass). From Prof. S. B. Buckley, Austin, Tex. 1878. 
2. Paspalum leve (Water Grass). From the Eastern Experimental Farm, West 
Grove, Chester County, Pa. 1880, August 23-29. 
3. Paspalum dilatatum. From S. L. Goodale, Saco, Me. 1880. 
4, Paspalum praecox. From Charles Mohr, Mobile, Ala. 1879. 
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