The New York herald., 1844-07-17

THE GREAT GAS MICROSCOPIC APPARATUS
As we promised we have procured the following
description of this splend apparatus. The objecl
of the instrument is to present to large assem-
bly, the minutest objects OF nature, and the most
delicate productions OF art magnifed to such an
extent, that the finest details OF the structure shall
ne distinctly. visible to all present This Is accom-
pished by giving to the microscope the form OF the
magic lantern, throwing the magnifed object on al
extensive surface coated with white paint. To ef
feet this, two things are Indispensable the
object which is to be magnlfed must be so in
tensely Illuminated that when the light collected
upon it has been dinsed over the enlarged surface,
it will still be sufficiently bright to produce easy
vision; and, secondly, the microscope to which
the object thus Illuminated is exposed, must be
CONSTRUCTED with such exquisite perfection that the
magnled object may retain all its natural precision
and be free from the frnges Of prlsmatic color,
which attend all ordinary of refraction. Let
us see, then, how these two objects are attained.
The illuminating apparatus consists OF a drum
mond light of extraordinary power, whose rays are
condensed upon the object by large lenses resem-
bling powerful burning lenses. A cyender of pure
lime an inch in diameter, is kept in slow revolu-
tion by clock work. 1t receives the fame OF a
strong compound blowplpe, by which it is heated
until it becomes intensely luminous. In front OF
this placed two enormous lenses of the purest
glass, each of which presents to the light surface
of nearly an hundred circular inches. These col
lect to focus the cone OF rays which falls upon
them and condense IL on the object Supposlng the
object TO have diameter OF the tenth OF an inch, il
VIII ny tillS dIIdUgtIntut IcceVe upon ~ nearly
ten thousand times more light than it would re-
ceve directly from the burner If placed in the
place of the lens. But with this immense illum-
mating power, heating influence would be
unavoidaby produced, which would Instantly
kill any living object, and scorch and de-
troy any prepared one. This is prevented by In
rerposing, between the lenses and the object, a
caLal Of highly transparent saline solution, by
passing through which the light is strained of its
neat The illumination being thus effected and
he object kept cool, the microscopes are intro
1uced before il, and the enlarged representation
,roduced and exhibited on the whtened surface
| graduated powers in the present apparatus-the
over adapted TO the larger, and the higher to the
| more minute classes of objects. Each of these s
composed of two plano.convex lenses, each OF
which lenses is itself double triple. being chro-
matte in the most perfect degree. With the lower
powers, the butterfly tribe, locusis leaves Of vege-
tables and chemical processes, such the decom-
position of water, are shown. With the higher
powers, the more minute objects, such as animal
| cules in water, eels in paste, small insects,
Sc., &c, are exhibited The lenses of the
highest power arc so minute, that to exhibit with
them an insect one tenth OF an inch in length, the
object which will be seen, not all at once, Che
magnitude being far too great to permit that) bu
| ike moving panorama
The apparatus Is accompanied by cabinet fur
nlshed with a large collection of prepared objects
including various insects, sections of wood, wings,
feathers fossils, cells for living anmacules, means
| of exhibiting artificial objects, crystallisaon Of
salts, chemical decomposition, &c.
The Croton water as II comes from the hydrants
will be exhibited this evening, when lecture on
| water will be given.