— 4 — ■ 
There are many things in this bulletin which are only 
tentative, but they are the best results which we have ob* 
tained, and we give them as such without any apology ex- 
cept that we regret that our investigations have not been 
pushed so far as we have desired to push them. 
I have no doubt but that some intelligent critic, with 
strongly utilitarian proclivities, will ask what value such 
work may be to the farmer; and possibly add, to any one 
else? There may also be a goodly number, other than the 
farmers and critics, who have but little sympathy with the 
class of effort recorded in these pages. I am aware that 
cattle will feed upon hay just as in the past and that the 
feeders will probably pay little heed to questions of compo- 
sition as given in the fuller analyses ; possibly but little more 
than the average man does to the same questions expressed 
in the terms of the analyses now in vogue. In spite of this, 
there is a satisfaction in finding out, with some degree of 
definiteness, what we mean by the old terms, such as nitro- 
gen-free extract, crude fiber, etc. These have been useful 
terms, very convenient ones, under which to include much 
that we did not know about a fodder. If this line of work 
has no other commendation, it is an attempt to find out how 
much we do not know, and to which we have made no pre- 
tense of knowledge, and also some of our misconceptions. 
In the closing paragraphs of Bulletin No. 35, I called 
attention to the variations in the composition of alfalfa hay 
grown in different localities, and the anal}'ses given cover a 
period of about ten years — 1886-1896. It would seem that 
the analyses recorded in this period ought to represent with 
a fair degree of accuracy the composition of the plant as 
grown in this country: but there is such a wide range in its 
composition that the suggestion is near at hand that the 
variation in composition is due to climatic conditions, and 
not to differences in the soils. We have extended our ob- 
servations to observe these effects, and not simply to in- 
crease the number of analyses of alfalfa, which seems to us 
altogether useless. 
It is true that there are variations in the climate of a lo- 
cality from year to year ; still the climatic conditions of a 
given locality are. in the main, quite constant in their gen- 
eral character, and we reduce the climatic effects to this 
minimum by making observations upon the plant grown in 
the same locality, and. contrariwise, we gain information on 
this very point by taking our samples from the same plot of 
ground. 
Our samples of alfalfa hay showed, in comparison with 
