hite of the paper and the black of the
characters, various experiments have been made in the introduction of
colored papers. M. Javel advises the adoption of a slightly yellow
tint. But the nature of the yellow to be used is not a matter of
indifference; he would desire a yellow resulting from the absence of
the blue rays, analogous to that of paper made from a wood paste, and
which is often mistakenly corrected by the addition of an ultramarine
blue, which produces gray and not white. M. Javel has been led to this
conclusion both from practical observation and also theoretically from
the relation which must exist between the two eyes and the colors of
the spectrum. His third advice is to give preference to small volumes
which can be held in the hand, which obviates the necessity of the
book being kept fixed in one place, and the fatigue resulting from
accidental images. Lastly, M. Javel advises the avoidance of too long
lines, and therefore he prefers small volumes, and for the same reason
those journals which are printed in narrow columns. Of course every
one knows that it is exceedingly injurious to read with insufficient
light, or to use too small print, and other common rules. M. Javel
concludes by protesting against an invidious assertion which has
recently been made "in a neighboring country," according to which the
degree of civilization of a people is proportional to the number of
the short sighted shown to exist by statistics; the extreme economy of
light, the abuse of reading to the detriment of reflection and the
observation of real facts, the employment of Gothic characters and of
a too broad column for books and journals, are the conditions which,
M. Javel believes, lead to myopy, especially if successive generations
have been subjected to these injurious influences.

* * * * *

PHOSPHORESCENCE.

M. Nuesch records, in a recent number of the _Journal de Pharmacie_,
some curious observations regarding luminous bacteria in fresh meat.
Some pork cutlets, he found, illuminated his kitchen so that he could
read the time on his watch. The butcher who sent the meat told him the
phosphorescence was first observed in a cellar, where he kept scraps
for making sausages. By degrees all his meat became phosphorescent,
and fresh meat from distant towns got into the same state. On
scratching the surface or wiping it vigorously, the phosphorescence
disappears for a time; and the bu