THE AUSTRALIAN NATURALIST. 73 
face. Stronger solutions can be used with some insects and 
will be more permanent in their protective power. I have at 
last come across a medium which appears to be fairly lasting in 
‘character, not to corrode the pins, and not to disfigure the 
specimens. This consists of a very simple preparation, a satu- 
rated solution of common white arsenic in methylated spirit. 
A little white arsenic is placed in a bottle which is filled up 
with spirit and well shaken at intervals for a day or so. The 
~clear solution after the surplus arsenic has settled to the bot- 
tom, is used. The best plan for beetles, flies, ants, and such 
like, is to place some of the poisoned spirit in a glass, kept 
for that purpose alone, and, taking the insect up by catching 
“the pin on which it is set with the forceps, to dip it gently: 
in the spirit so as to completely wet it; the insect may then 
be placed direct in the cabinet. Carded specimens are treated 
in the same manner. Butterflies and moths may also be 
treated in the same manner, and after drying there is but 
little clogging of the down. If preferred, however, the bodies ~ 
can be painted on the undersurface with the spirit, by meang 
-of a soft camel-hair brush, the antennae also being touched. 
For large specimens or those already set out in the cabinet, a 
small dropping-tube with rubber bulb, such as is commonly 
used for filling fountain pens, answers admirably. The spirit 
~can be very neatly and expeditiously dropped over the speci- 
mens so as to thoroughly moisten them. A little excess falling 
on the paper of the drawer does no harm, as rt soon dries and 
leaves no stain. The arsenical spirit, being highly poisonous, 
should be carefully labelled, and with the glasses and appli- 
-ances used for applying it, kept in a safe place. It would 
hardly be advisable to use this substance on the scale of a her- 
‘barium, for preserving plants which are usually kept some-, 
what loosely packed, as there might possibly be a sufficient 
- evolution of arsenical vapour to be injurious in a close room. 
Insects, however, are so much smaller in bulk and are always 
kept in fairly tight cases, and I have never experienced the 
slightest ill effects, though I have used the solution somewhat 
extensively for a long time past. I exhibit a case of miscel- 
laneous insects which have been treated by the method de- 
scribed, and have remained thoroughly protected for a period 
. greatly exceeding that during which corrosive sublimate would 
have been efficient. I cannot yet say in how far the arsenical 
solution will be permanent in its effects, but it is at any rate 
considerably more so than corrosive sublimate. I have by its 
use protected specimens for at least six times as long as I have 
found the latter substance effective, and it will at least con- 
siderably reduce the labour of keeping a collection safe. 
I may add that ! am at present experimenting with a num- 
ber of other substances, with a view to finding one with the 
necessary qualifications which will be quite permanent in its 
~effects. 
