230 
POPULAR SCIENCE REVIEW. 
fluids, in the very disorganizations which slowly ruin this goodly human 
frame, the microscope discovers forms of the highest geometrical accuracy, 
as well as of the most delicate beauty. And this beauty and consummate 
finish are everywhere, and are found farther and deeper as our powers 
increase of observing them. Here, too, at every step we find the limitation 
of our own powers, and the illimitable field of nature ; the infinite con- 
trasting with our finite, teaching us ‘ the moral lesson of science, — 
humility.’ ” 
Manchester Literary and Philosophical Society, Microscopical Section.— 
With the permission of the author, we reprint the following paper “ On 
Preparing and Mounting Insects,” by Mr. Hepwortii : — 
“ I herewith send you a specimen, for the inspection of the Microsco- 
pical section of the Literary and Philosophical Society, regretting I have 
not a duplicate to present to the members. Having seen and purchased 
some whole insects mounted by some gentleman (unknown to me) so beau- 
tifully, it caused me to make a series of experiments, which have resulted 
in producing the specimen before you. Although I have mounted great 
numbers, our unknown friend still bears the palm. The plan I have 
adopted, and which has been as yet the most successful, is the following : 
After destroying the insects in sulphuric ether (methylated being cheaper), 
wash them thoroughly in a wide-necked bottle (half-filled) with two or 
three waters ; the delicate ones require great care. Then immerse them 
in liquid potash (or Brandishe’s solution, which is stronger than the usual 
preparation), and let them remain a longer or shorter time, according to 
their texture. Whenrcady to remove, put them one by oneinto asmall saucer 
of clear water, and with a camel-hair pencil in each hand press them flat 
to the bottom, holding the head and thorax with the left-hand brush, and 
apply pressure with the other from above, downwards, giving the brush a 
rolling motion, which generally expels the contents of the abdomen dis- 
solved by the potash. If you stroke the parts you are apt to separate the 
abdomen from the thorax. A minute roller of pith or cork might be used 
instead of the brush. In larger objects, use the end of the finger to flatten 
them. Large objects require more frequent washings, as it is desirable to 
remove the potash thoroughly, or crystals are apt to form after mounting. 
Having placed them on the slides with thin glass covers, tied down with 
thread, dry and immerse them in rectified spirit of turpentine ; place the 
vessel under the receiver of an air-pump, and keep it exhausted until the 
turpentine has taken the place of the air bubbles : they are then ready for 
the application of the balsam. Larger objects may often, with advantage, 
be transferred to a clean slide ; as, during the drying, there is considerable 
contraction, and an outline often remains beyond the margin showing 
this. When closely corked they may remain in the spirit for two or three 
months. As you take them from the bottle, wipe as much turpentine off 
as possible before removing the thread ; and when untied, carefully wipe 
again, placing the finger on one end of the cover whilst you wipe the other, 
and vice versd. By this means you remove as much turpentine from under 
the cover as is necessary ; then drop the balsam, thinned with chloroform, 
upon the slide, letting the fluid touch the cover, when it will be taken in 
between the surfaces by capillary attraction ; and after pressing the cover 
down it may be left to dry, or you may hold the slide over a spirit-lamp 
for a few seconds before pressing down the cover. If heat is not applied 
they are much longer in drying, but are more transparent. If made too hot 
the boiling disarranges the objects, and if carried too far will leave only the 
resin of the balsam, rendering it so brittle that the cover is apt to fly off 
by a fall, or any jar producing sufficient percussion. Never lift the cover 
up if possible during the operation, as there is danger of admitting air. A 
