By F. VANDERPOEL, of Newark, New Jersey.
In the February number of this _Journal_ the writer described a new
settling tube for urinary deposits which possessed several advantages
over the old method with conical test-glass and pipette. For several
reasons, however, the article was not illustrated, and it is for the
purpose of elucidation by means of illustration, as well as to bring
before the readers of the _Journal_ two new and improved forms of the
tube, that space in these columns is again sought. The first two of the
figures, 1 and 2, represent the tube as originally devised; 1 denoting
the tube with movable cap secured to it by means of a rubber band, and 2
the tube with a ground glass cap and stop cock. The first departure from
these forms is shown at 3, and consists of a conical tube, as before, but
provided with a perforated stopper, the side opening in which
communicates with a side tube. The perforation in the stopper, which is
easily made by a glass blower, thus allows the overflow, when the stopper
is inserted into the full tube, to pass into the side tube. The stopper
is then turned so as to cut off the urine in the latter from that in the
large tube, and the latter is thus made tight. After allowing it to
remain at rest long enough to permit subsidence of all that will settle,
the stopper is gently turned and a drop taken off the lower end upon a
slide, to be examined at leisure with the microscope. The cap, ground and
fitted upon the lower end, is put there as a precautionary measure, as
will be seen farther on.
[Illustration: VANDERPOEL'S SETTLING TUBES.]
The tube shown at 4 is, we think, an improvement upon all of the
foregoing, for upon it there is no side tube to break off, and everything
is comprised in a small space. As will be seen by referring to the
figure, there is a slight enlargement in the ground portion of the
stopper end of the tube, this protuberance coming down about one-half the
length of the stopper, which is solid and ground to fit perfectly. The
lower half, however, is provided with a small longitudinal slit or
groove, the lower end of which communicates with the interior of the
tube, while the upper end just reaches 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.]