— 13 
those samples prepared in i8q6, which have about the same 
percentage of water. But this compels us to assert that 
the sealing of the bottles was of no avail at all and disre- 
gards the increase in the percentage of nitrogen in the dry 
matter, which seems to us fully established. The differ- 
ences cannot be attributed to the different methods of de- 
termination, nor yet to the operator, as the same person, 
my assistant, Mr. Ryan, made the two series of determina- 
tions by the same method and always in duplicate. 
While this subject may be more interesting to the in- 
vestigator in the domain of agricultural science than to 
the practical agriculturist, we regret having been unable to 
pursue it to no greater extent. 
AR'riFiciAL di(;ksti()X of alfalfa hav. 
It is not our purpose to discuss the relative merits of ar- 
tificial compared with animal digestion, but if we confine 
ourselves to the question of the pepsin digestion of the albu- 
minoids, it is certainly more agreeable, more satisfactor}' in 
that it can readily be applied to a much larger range of 
samples in a short time, and has the further advantage that 
the different samples can be subjected to the same conditions. 
The commercial pepsin preparations may vary in quality 
very greatly, but the pepsin can be tested before it is used 
quite as easily as any other chemical reagent. 
We undertook the investigation to discover whether 
there is any difference in the digestibility of the three cut- 
tings of alfalfa hay or in alfalfa hay of different ages. The 
samples employed in this work were new hay, one-year-old 
hay, and two-year-old ha}-. These terms, new hay, one-year- 
old hay, and two-year-old hay, are to be understood in their 
ordinary sense, and not that a sample of alfalfa was made 
into hay and its digestibility determined forthwith, for such 
was not the case. The samples were taken in the years of 
t8q4, i8qs» ai^d i8c)6, and the determinations were made in 
the last year. 
'niK MIVI'HOO. 
We followed the method in general use -digestion with 
a dilute hydric chlorid solution of pepsin. After an ex- 
tended series of experiments with coagulated egg albumen, 
we adopted the following method as givingthe best results. 
We dissolved five grams of scale pepsin in one litre of two- 
tenths per cent, hydric chlorid and to five grams of alfalfa, 
ground as fine as possible, we added 150 cc. of the pepsin so- 
lution, and digested it for eight hours at forty degrees C., 
adding, during the eight hours, .7 grams of hydric chlorid. 
