602 
Journal of Agricultural Research 
Vol. XXVII, No. S 
to be 99 per cent pure by both the Munson-Walker-Bertrand method 
and the Benedict method. ’It was fed with the mash at noon. The 
results are reported in grams of lactose excreted during the experiment. 
As would be expected from the fact that the determination of reducing 
sugars is affected by uric acid in the Munson-Walker-Bertrand method, 
while this acid does not affect, appreciably, the Benedict method, the 
results obtained by the latter method are, with few exceptions, much 
lower than those obtained by the former. On a comparative basis, 
however, the differences between experiments are as well shown by the 
one method as by the other. In the preparation of the osazones for the 
identification of individual sugars in the extracts the utmost care was 
taken, for this method of distinguishing between the sugars has never 
proved to be infallible in this laboratory, and especially was this found to 
be the case with extracts such as those dealt with in this investigation. 
The purified free base was used since it was found to give more satis¬ 
factory results than the hydrochlorid. While the qualitative osazone 
tests were not quite as satisfactory as might be desired, they confirm 
very well the quantitative data. In general, they indicate that lactose 
does not appear in the exqreta of hens until comparatively large amounts 
are fed, that the glucosazone usually is found whenever the lactosazone 
is present, and that glucose persists in the excreta for some time after the 
lactose has disappeared. 
In feeding lactose to hens it was immediately noticed that amounts 
exceeding 2 gm. daily caused diarrhea, a finding in agreement with that 
of Shaw (7). In order to test the possibility of the diarrhea itself being 
the cause of an increase in the excretion of reducing substances, two 
experiments, in which diarrhea was caused by feeding Epsom salts 
(MgS 0 4 .7H 2 0) in the drinking water, were made. The results indi¬ 
cated clearly that the diarrhea was not the cause of the excretion of 
comparatively large amounts of reducing substances when lactose ex¬ 
ceeding 2 gm. was fed. 
The results of seven experiments, summarized in Table III, show that 
pure lactose when added to a cereal diet is utilized to a large extent by 
hens. All hens excreted more or less reducing substances when fed a 
normal cereal diet; this was, of course, expected. The amounts of re¬ 
ducing substances excreted by the four hens in three seven-day experi¬ 
ments on the lactose-free diet varied from 0.56 gm. (calculated as 
lactose) to 1.68 gm. by the Benedict method, as indicated in the follow¬ 
ing summary: 
Hen No. 
Experiment. 
Average. 
III. 
V. 
VII. 
I . . . 
Gm. 
i- 34 
1. 40 
0. 60 
0. 72 
Gm. 
O. 56 
i- 33 
1. 68 
1. 05 
Gm. 
O. 70 
I. 26 
O. 98 
I. 61 
Gm. 
0. 87 
I* 33 
1. 09 
I- 13 
2. 
% . 
4 . 
Average. 
1. 10 
! 
