Each eye will then see only the image responding to the coloration chosen, and, as it is precisely the one which has the perspective proper to it, the relief appears immediately.  The effect is striking.  We perceive a diffused image upon the screen with the naked eye, but as soon as we use one special eye-glass the relief appears with as much distinctness as in the best stereoscope.  One must not, for example, reverse his eye-glass, for if (things being arranged as we have said) he looks through a red glass before his right eye, and through a green one before his left, it is the image carrying the perspective designed for the right eye that will be seen by the left eye, and reciprocally.  There is then produced, especially with certain images, a very curious effect of reversed perspective, the background coming to the front.

Now that photography is within every one’s reach, and that many amateurs are making stereopticon views and own projection lanterns, we are persuaded that the experiment will be much more successful than it formerly was.  An assemblage of persons all provided with colored eye-glasses is quite curious to contemplate.  Our engraving represents a stereopticon seance, and the draughtsman has well rendered the effect of the two luminous and differently colored fascicles superposed upon the screen.

In a preceding note upon the same subject, Mr. Hospitalier remarked that upon combining these effects of perspective with those of the praxinoscope, which give the sensation of motion, we would obtain entirely new effects.  It would be perhaps complicated as to the installation, and especially as to the making of the images, but, in certain special cases (for giving the effect of a machine in motion, for example), it might render genuine services.—­La Nature.

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THE EFFECT ON FOWLS OF NITROGENOUS AND CARBONACEOUS RATIONS.[1]

[Footnote 1:  This article is condensed by permission from a thesis prepared for the degree of Bachelor of Science in Agriculture, by James Edward Rice, a graduate of the class of 1890.  The work was planned and wholly carried out in the most careful manner by Mr. Rice under the immediate supervision of the Director.  The results have been thought worthy of publication in the Cornell Station Bulletin.]

On July 2, 1889, ten Plymouth Rock hens, one year old, and as nearly as possible of uniform size, were selected from a flock of thirty-five.  At the same time ten chickens, hatched from the same hens mated with a Plymouth Rock cock, were similarly chosen.  The chickens were about six weeks old, healthy and vigorous and of nearly the same size.  Up to the time of purchase both hens and chickens had full run of the farm.  The hens foraged for themselves and were given no food; the chickens had been fed corn meal dough, sour milk and table scraps.