Evening star. [volume] (Washington, D.C.) 1854-1972, 1911-11-30
CL0SE-RANGE VIEW
Scientists Inspect Laboratories
in Agricultural Department.
DIVISION OF TECHNOLOGY
Visitors From Other Bureaus Have
Special Apparatus Explained.
EXPERTS AND THEIR PRODUCTS
Freezing Microtome and It's Uses.
Experiments With Cotton.
Paper-Making Exhibit.
EXPERTS AND THEIR PRODUCTS

This was visiting day in the Depart
ment of Agriculture. That is not exactly
what it was called. In fact, it his not
yet been officially designated. but it was
the day when the scientists of the de-
partment were given a chance to see
what was doing outside their own labora-
tories. 1t is part of new system that
has been started in the department and
that is working to the great satisfaction
Of all the scientists concerned.
Beginning at / o'clock, the scientists
from the various divisions were invited
to inspect the special apparatus in the d.
vision OF agricultural technology. The
same thing has been done previously with
other divisions, the idea being to give
the expert workers of the department
notion of what is going on outside their
| own divisions, to let them see the spe-
cial apparatus used on the chance hey
may want to adapt some of it to their
own use and to prevent duplication of
work in special lines.
The same thing has been done previous
| ly in the d visions of DIR. Orion Of plant
disease investigation and Dr. Rodney
True Of the drug and poisonous plant
| Investigations, and in some of the
other laboratories. The Department of
there are so many varied interests work
ing along different lines that scientist
might easily work in laboratory half
a generation and not know what the
man down the corridor was doing and
how he was doing it,
Employ Special Apparatus.
All of the laboratories have developed
special apparatus for doing different sorts
of scientific work. apparatus that has to
be made especially for them and that is
found nowhere else. At the same time
there are many scientific wrinkles devel-
oped in one division that with little
where. The scientists who accepted the
visiting invitation were taken In punches
Of eight and introduced to the different
laboratories. Here the specialist In
charge had his instruments. or some of
the more special ones, displayed on the
work tables. The visitors were given an
explanation Of the uses and advantages of
the special instruments and were then
passed on to another laboratory, where
the process was repeated and fresh
party was shown through the first room.
Everything was Informal. The trip
through the whole divis on did not take
more than an hour, and every visitor
knew what was being done in the di-
vision and whether there was anything
in the way of special apparatus of which
he could make use.
DR.. n. A. Cobb, in charge Of the d.
vision, was the host and the visitors saw
everything there was to see, from high
power microscopes to cotton MS In
fact the microscope was one of the things
in which the visitors were most generally
interested, because the microscope is so
generally used In modern scientific re-
search.
Black Microscope Best.
One Of the simplest and at the same
time a very useful innovation shown was
the black microscope. Those familiar
with microscopes are used to seeing tubes
Of highly polished brass and everything
about the instrument FURNISHED to the
last degree The scientists who have to
work for hours with microscope have
found that the bright surfaces tire the
eye and throw an investigator out of
sorts in a fraction Of the time a dead
black instrument takes. Therefore, the
instruments have been made black, which
is not pretty, but effective.
Another thing that was simple, but use
full. was a head rest for a copying mi
croscope. The instrument Is set in novel
fashion. 1t is in an alcove by window
on a heavy table, counterbalanced by
iron weights. The table Is adjusted at
the most convenient height and then
clamped with set screws to the wall Of
the building, so it is solid as the wall it
self. There is complicated arrange
ment of mirrors and prislns that throw
the image of the specimen being exam
ined on a sheet of paper, and the OBJ
server can trace the outline accurately
with pencil. There is an obscure group
of earthworns, about which little is
known except that they have an impor-
tant bearing on agriculture. Most of
them are of microscopic size, but pictures
of them made with the tracing micro
scope look like miniatures of the sea
serpent.
Effect of Spray of Ether.
In connection with the microscopic
work there is the freezing microtome
Some of the specimens are set in gelatin
and this is thrown on little metal knob
on small polished table. A spray of
ether is blown against the lower part of
the knob and the temperature lowered
until the gelatin freezes, when it is cut
into thin shavIngs by a microtome knife
adjusted by a micrometer screw.
But the real thing in microtomes is an
instrument where the specimens are pre-
served In Jumps of paratfin. Connected
with this there Is a small box full of ice,
and through the ice a blast of cold air
Is turned on the paraffin. Tbs keeps 1t
at just the right temperature for cutting
microscope sections; The microtome
adjusted to cut sections one-ffth the
thickness of sheet Of cigarette paper.
1t can do better than that, but the scien-
lists say greater thinness is di, ad-
vantage.
Some of the most modern and practical
things in the division are being done in
cotton and paper making. The depa t.
ment for over year has been max ng
standard samples OF the different grades
Of cotton. Previously there was no suca
thing as standard cotton sample, be-
cause there was no way of keeping a
cotton sample from de, eriorating. Now,
however. a committee of the greatest cot
ton experts in the country has made
set Of standard grades. and the division
has found a way of preserving them n
definitely by sealing them up in thin
glass tubes, bigger in diameter than a
l00-candlepower incandescent lamp AMI
then. like the lamp globe. exhausting the
air and leaving the sample in a vacuum.