136 Dr Traill on the Preservation of Zoological 
every collector; and various methods have been proposed of 
accomplishing this desirable object. The compositions into 
which arsenic and corrosive sublimate cf mercury enter, are well 
known to be very effectual, when properly applied ; but, unless 
used with caution, they are apt to injure the natural pliancy of 
the skins, and they can scarcely be effectually employed to pro- 
tect collections of insects. I have known these substances, even 
in the hands of the most expert, produce such tenderness of the 
skins impregnated with them, as to form a considerable ob- 
stacle to the setting up of the specimens. To render them ef- 
fectual, too, they must be carefully applied to each specimen ; 
by which the labour of collecting and preserving is materially 
increased. 
Of the method proposed, by M. Temminck, viz. the introduc- 
tion of tallow into the cases containing zoological specimens, I 
am yet unable to speak from experience. It has been lately in- 
troduced into the Museum of our Royal Institution, where 
it will have a fair trial, although I confess that its modus ope- 
randi does not seem very obvious *. 
Camphor has been long known as a preservative against the 
attacks of insects ; yet I have known specimens of birds to suf- 
fer from moths, though inclosed in boxes in which camphor was 
present ; and, to be efficacious, it ought to be used in consider- 
able quantity. 
Every substance which I have yet tried, seems to be inferior 
in efficacy and ease of application to the following, — the method 
of Mr William Gibson, preparer of objects of Natural History, 
residing in No. 16, London Road, Liverpool,— -which I shall 
transcribe from his own communication to me. 
“ I have found,” says he, 66 that nothing destroys insects so 
effectually as red fed oil of turpentine, and my method of using 
it is as follows : I put the turpentine in a bladder, the mouth of 
which is firmly tied with a waxed string ; and nothing more is 
necessary than to place the bladder, thus prepared, in the box 
with the birds, or to tie it to the pedestal on which the birds 
are perched, in a case. If there be any maggots on the birds, 
* I did not find, after many trials, that tallow placed in cases containing zoologi- 
cal specimens does any good Ed. 
