38 
IIalph_, on Mounting Objects. 
white or opaque under its action^ I transfer them to rectified 
spirits of wine_, and_, after a good soaking^ employ turpentine, 
and vice versa. 
Again, the best way I know of preparing the feet of Insects, 
&c., is first to wash the feet, while the insect is alive, with 
spirits of wine, then holding it by a pair of forceps close 
to the edge of a clean piece of glass, the insect will lay 
hold of the upper surface by its foot, then suddenly drop 
another small piece of glass over it, so as to retain the foot 
expanded, and cut it off with a pair of scissors, tie up, and 
soak to get rid of air. 
The tongues of flies are most easily made to protrude by 
pressing the head between the finger and thumb, over the eyes, 
or with a pair of forceps ; the air appears to be forced into 
the trachea, and distends this organ freely, when it may be 
laid on a piece of glass, another placed over it, and then 
severed from the insect and subjected to the turpentine pro- 
cess. 
With regard to vegetable tissues, I have had much diffi- 
culty, and shall be glad to obtain more information. My de- 
sire has been to obtain such a medium as will solidify or 
viscify around a specimen which has been previously pre- 
pared in glycerine, and such a medium must not disagree 
with the glycerine so as to exhibit oily globules, &c. At 
present, I cement glycerine contained in cells with mastic 
dissolved in creosote, the glass cover generally projecting 
over the edge of the cell, so as to allow the mastic to surround 
the edge of the cover both above and below. I am inclined 
to think that those glycerine-prepared specimens keep best 
which are mounted in a cell with a small bubble of air con- 
tained, as I think the glycerine does not escape so freely ; 
the escape of glycerine from apparently well- secured cells, 
appears to me to be due to its great expansive property, 
besides its tendency to deliquesce. 
March, 1857. 
Since I wrote the above, some months ago, I have made a 
decided advance in the preparation of some insect-tissues. I 
adopt the following plan : Place the insect alive in sweet 
spirits of nitre ; it will die rapidly, and the air will be freely 
expelled, partly by reason of the volatility of the medium, 
and those with a proboscis, &c., will protrude it. After 
soaking a day, the specimens are to be rapidly transferred to 
a small quantity of clean spirits of turpentine, when all the 
sweet spirits of nitre will be expelled in the form of globules 
charged with grease ; immerse in a further supply of tur- 
