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.
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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 mixtures of ethylene with either hydrogen carbonic oxide or marsh-gas is less than that of pure ethylene. (3.) That when the proportion of ethylene in such mixtures is above 63 per cent. the illuminating power of the mixture is but slightly affected by the nature of the diluent. When, on the other hand, the proportion of ethylene in such mixtures is low, the illuminating power of the mixture is considerably the highest when marsh-gas is the diluent, and the lowest when the ethylene is mixed with carbonic oxide. (4.) That if 5 cubic feet of ethylene be uniformly consumed irrespectively of the composition of the mixture, the calculated illuminating power is in every