106 BULLETIN OF THE BUSSEY INSTITUTION. 
fancied also that the conflicting statements of chemists as to the 
presence or absence of sugar in grasses might perhaps be com- 
posed if it could be ascertained at what times and stages of 
development some part of the sugars in young grass might 
change to mannite. 
Old and New Oat Grain Contrasted. 
It is not alone as regards new and old hay that practical men 
note a marked difference in respect to physiological properties 
which must depend on differences in chemical composition. These 
differences are exaggerated in oat grain according as it is new or 
old. It is a well-known fact that oats which have recently been 
harvested have a laxative and ‘‘ softening” effect on horses. 
They are regarded as quite unfit to be given to animals that 
have to perform hard work. It is only after oats have been kept 
for some time in store that they become really fit for use. 
In the hope of throwing some light on this matter, ‘‘ old oats” 
of the crop of 1903, bought in August, 1904, were tested for 
mannite in contrast with ‘‘ new oats ” of the crop of 1904, bought 
early in September, 1904. But no mannite was detected in either 
of these samples. 
200 germ. of each of the specimens were weighed out and ground 
to coarse meal. A percolator full of the old oats amounting to 
150 grm. was percolated with hot water without much trouble 
though the operation was slow, while the remaining 50 grm. were 
leached by way of decantation with small successive portions of 
boiling water. 
The meal from the new oats, on the contrary, formed a thick 
pasty mass on being treated with hot water and could not be per- 
colated. Hence the whole 200 grm. were leached with successive 
portions of hot water. In both cases, the solutions were filtered 
and evaporated to a volume of almost 100 cc. before being treated 
with the ammoniacal copper sulphate, which seemed to the eye to 
give a somewhat larger (bluish) precipitate in the case of the new 
oats than was the (greenish) precipitate obtained from the old oats. 
But on treating these precipitates in the usual way no indications 
of the presence of mannite could be detected in either of them. 
