and increase in digestible" so much spoken of is, so far as our
present very imperfect methods of analyzing these compounds permit us
to judge, a myth; and I have not yet found any sufficient evidence to
support this statement. A loss, then, of 6 parts of organic matter out
of every 106 parts put into the silo has in this instance taken place,
due chiefly to the decomposition of starch, sugar, and mucilage, etc.
And as the grass contained 70 parts of water when put into the silo,
the total loss would only be 1.7 per cent. of the total weight. This
theoretical deduction was found by practical experience correct, for
Mr. Smith, agent to Lord Egerton, upon whose estate this silage was
made, in his report to Mr. Jenkins says the "actual weight out of the
silo corresponds exactly with the weight we put into the same."

In my judgment these figures are of interest to the agricultural
chemist for many reasons. First, they will clear the ground for future
workers and eliminate from their researches what would have greatly
complicated them--changes in the cellulose bodies.

Secondly, they are of interest because our present methods of
distinguishing between and estimating digestible and indigestible
fiber is most rough, and probably inaccurate, and may not in the least
represent the power of an animal--say a cow--to digest these various
substances; and most of us know that when a new method of analysis
becomes a necessity, a new method is generally discovered. Lastly,
they are of interest to the agriculturist, for they point out, I
believe for the first time, the exact amount of loss which grass--or
at least one sample--has undergone in conversion into silage, and also
that much of the nitrogenous matter is changed, and so far as we know
at present, lost its nutritive value. This, however, is only comparing
silage with grass. What is wanted is to compare silage with hay--both
made out of the same grass. Then, and then only, will it be possible
to sum up the relative advantages or disadvantages of the two methods
of preserving grass as food for cattle.--_Chem. News_.

* * * * *

THE ILLUMINATING POWER OF ETHYLENE.

Dr. Percy Frankland has obtained results which may be thus briefly
summarized: (1.) That pure ethylene, when burnt at the rate of 5 cubic
feet per hour from a Referee's Argand burner, emits a light of 68.5
standard candles. (2.) That the illuminating power of equal volumes of