method of constructing the
school room and of conducting the same. I never could understand why
children of the primary age are kept sitting on benches for a large
number of hours at a time. School houses ought to be built like the
hospital building at the corner of Lexington avenue and Forty-second
street, used for cripples, where there is in the upper story a large
room, called the solarium, which is in fact a large play room, exposed
to the sun, where these little ones are kept the greater part of the
time. The upper story of the school houses should be so constructed;
and children should be encouraged to bring their toys and playthings
with them; and then, instead of changing the age of admission from four
years, it might be kept as it is; and instead of shortening the hours
of attendance, lengthen them. Of course it should be taken for granted
that the school house is constructed for the accommodation of the poor
children, and in this light it would be better that such children
should spend most of the day in school houses having good sanitary
conditions, rather than, as they now do, in tenement houses. Thus you
would have these primary schools with plenty of air and light, which
you can get in the upper story, and children would be glad to come
early, and remain until three or four o'clock, or even later in the
afternoon."

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MICROSCOPIC COMPARISON OF BLOOD CORPUSCLES.

Dr. J. G. Richardson of Philadelphia, whose views upon the subject of
proving blood stains by the use of the microscope have been described
in this Miscellany, has lately prepared slides for the microscope so as
to show blood corpuscles from two different animals on the same field.
He did this by flowing two drops of blood down the slide, and nearly in
contact. Dr. C. L. Mees has modified this proceeding. He spreads the
blood by Johnston's method, which is to touch a drop of blood to the
accurately ground edge of a slide, and then draw it gently over the
face of the other slide, leaving a beautifully spread film. In this way
one kind of blood is spread upon the slide, and another on the cover.
When dry, one half of each is carefully scraped off with a smoothly
sharpened knife, and the cover inverted upon the slide in such position
as to bring the remaining portions of the film into apposition. When
thus prepared the magnified image can be photographed.

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