~ > Py ae ¥ 
sae esd ae ) a SAS Bi. 
5 el et - vie 
146 THE MICROSCOPE. 
they are in flight, which the gentleman accomplishes by dropping 
them through a long glass tube into boiling water. The elytra and 
wings are by this means immovably fixed in the extended position, 
and remain unalterated during the subsequent operations. The body 
of the insect is then injected hypodermically with a strong solution — 
of caustic potash and allowed to remain three or four hours, then 
transferred to a glass slip and gentle pressure applied, when the 
viscera and other tissues forming the interior of the body will be ex- 
pelled. To dehydrate or remove the watery portion, absolute alcohol 
is generally recommended, but the lecturer contended that it was ex- 
pensive and not always at hand, while equally good results would 
follow by placing an ounce or two of refined gelatin in a vessel, 
pouring on alcohol of 95 per cent., and immersing the object for a 
short time—the gelatin, from its affinity for water, absorbing that 
fluid from both the object and alcohol. 
The insect is then placed in oil of cloves to clear or render it 
transparent, and is ready for mounting permanently in balsam. By 
this method the insect is rendered entirely transparent, the peculiar 
geometrical marking of the wings, the abdominal and thoracic rings 
and the various parts forming the head and limbs are beautifully 
displayed. * 
In preparing the lepidoptera, a somewhat different course is 
pursued, as the wings of all butterflies and moths, being covered with 
easily detached scales, must be protected. The butterfly or moth is 
placed on a square of glass and liquid paraffin flowed carefully over 
the entire insect. After cooling, a small aperture is made, exposing 
a portion of the body, and caustic potash injected; the subsequent 
_ operations being the same as for beetles, excepting that sulphuric 
ether must be used to dissolve off the paraffin, leaving the soft, 
velvety covering of the wings unimpaired. ‘ 
In this manner are prepared the beetles, dragon-flies, bees, 
wasps, caterpillars, etc., and when mounted in balsam they form 
some of the most beautiful and instructive objects imaginable, 
whether viewed through the microscope or reflected on the screen. 
Mr. Leckenby exhibited many fine specimens of his handiness in 
preparing and mounting the different orders of the insect world, 
noticeable among which were a gigantic tarantula spider, several 
gorgeous members of the Papilio genus, fierce-looking dragon-flies, 
beetles, wasps and a large collection of small objects. 
The lecture was followed throughout with the closest attention, 
and at its conclusion the interest in the subject was so manifest and 
