Tue Microscope. 27 
wishing to take up the study of insects will find it of great 
advantage to purchase this volume of Science Gossip, and then 
cockroach in hand, go through the points mentioned. Even 
better would it be to take a grasshopper rather than a cockroach. 
The two belong to the same order, the Orthoptera, so that the 
same general account would in its broader features be applica- 
ble to both, while the points of difference would be such as to 
lead the student to rely on himself. 
Dissecting insects is not such a difficult task as many seem 
to suppose. The only instruments absolutely needed are a pair 
of fine scissors, a pair of fine pointed forceps, and a couple of 
sharp needles mounted in penholders. The dissection should be 
carried on under water. The plan for holding the object, which 
has been adopted by the writer, is very simple and very con- 
venient. An empty blacking box is filled to a depth of about 
an eighth of an inch with melted beeswax, and, while this is 
still in a liquid condition a grasshopper is placed in it in the 
desired condition and the whole left to cool, when hard, water 
is poured in and the dissection begun. The integument is 
removed from the portion of the insect above the wax by means 
of the scissors, great care being exercised not to injure the 
underlying tissues. Almost all subsequent operations can be 
carried on with the needles. _When one specimen is used up 
the wax is again melted and another insect inserted. 
In working out the details a magnifying glass carried on a 
suitable support will be necessay. Ordinary ingenuity will 
contrive a device which will prove as satisfactory as any of the 
more expensive socalled dissecting microscopes. For .the 
minute structure, the section knife, and the compound micro- 
scope will be required. The general technique necessary for 
this histological investigation will soon be described in the 
pages of this journal. 
BAcTERIA ON Corns.—Of all the nonsense which has enliv- 
ened the science of recent years there is none which excells the 
recent lucubrations of Dr. Paulus F. Reinsch, on the presence of 
Bacteria on coins. His article has been quoted and reprinted 
in numberless journals whose editors ought to have known 
better. Bacteria on coins? Of course there are. Bacteria are 
everywhere. Scrape your tongue and you will find more speci- 
mens than would accumulate on a considerable pile of dollars. 
