es the enlargement in the side of the
latter. Thus in one position of the stopper there is a communication
between the tube and the outer air, while in all other positions the tube
is quite shut. In all these tubes care must be taken to fill them
_completely_ with the urine, and to allow no bubbles of air to remain
therein.

The first of these settling tubes was made without the ground cap on the
lower end, the latter being inserted into a small test tube for safety.
At the suggestion of Mr. J.L. Smith the test tube was made a part of the
apparatus by fitting it (by grinding) upon the conical end, and in its
present form it serves to protect the latter from dust and to prevent
evaporation of the urine (or other liquid), and consequent deposition of
salts, if, for any reason, the user should allow the tube to remain
suspended for several days.

These tubes will be found very useful for collecting and concentrating
into a small bulk the sediment contained in any liquid, whether it be
composed of urinary deposits, diatoms in process of being cleaned, or any
thing of like nature; and, as the parts are all of glass, the strongest
acids may be used, excepting, of course, hydrofluoric acid, without harm
to the tubes.--_American Microscopical Journal_.

* * * * *

[Continued from SUPPLEMENT, No. 594, page 9491.]

CLIMATE IN ITS RELATION TO HEALTH. By G.V. POORE, M.D.

[Footnote: Three lectures before the Society of Arts, London. From the
Journal of the Society.]

LECTURE III. DISEASES CAUSED BY FLOATING MATTER IN THE AIR.

The information which modern methods of research have given us with
regard to the floating matter in the air is of an importance which cannot
be overestimated.

That the air is full of organic particles capable of life and growth is
now a matter of absolute certainty. It has long been a matter of
speculation, but there is a great difference between a fact and a
speculation. An eminent historian has recently deprecated the distinction
which is conventionally drawn between science and knowledge, but,
nevertheless, such a distinction is useful, and will continue to be
drawn. A man's head may be filled with various things. His inclination
may lead him, for example, to study archaic myths in the various dialects
which first gave them birth; he may have a fancy for committing to memory
the writings of authors on astrology, or the speculations of ancient
philosophers