Ralph, on Mounting Objects. 
37 
Canada balsam, thinned down or diluted with chloroform, 
to flow in till the object is surrounded by this medium, and 
the whole space under the cover occupied by it. The chloro- 
form rapidly evaporates, leaving the Canada balsam in the 
condition it was before mixture with the chloroform, and 
harder at the edges. Mem. This mixture of chloroform and 
Canada balsam should not be kept mixed as it is apt to be- 
come clouded after some time, although it has no prejudicial 
effect on the specimens when recently made. 
The advantage attending this process is well worthy of note, 
I. e., that no application of heat to the animal tissues is 
needed, and no coagulation of albuminous fluids, &c., can 
take place. Those who have laboured in making prepara- 
tions of various kinds can scarcely have failed in encountering 
some specimens difficult of preservation, such as tongues of 
mollusca, and other oily or fatty subjects. These, it is gene- 
rally known, may be cleaned by immersion in turpentine, but 
if heat be afterwards applied in putting them up, they are very 
apt to become turbid ; hence the value of the above process. 
I soak such fatty specimens in turpentine till I find them 
clean enough, but before this I wash the specimen clean with 
a brush dipped in turpentine, or, if spirits of wine or water is 
used, allow the specimen to dry first, before subjecting it to 
the turpentine. The object having been so cleaned and laid out 
on a small piece of glass, such as a piece of broken slide, place 
another piece of glass over it, and secure them by binding 
it round with fine silver wire (such as may be obtained by 
unwinding a harp string), and place the whole in a jar or 
wide-mouthed bottle filled with turpentine. When well 
soaked for several days, or it may be for weeks, take out, and 
carefully brush the specimen, if it requires and will bear it, 
to free it from turbid matters at the edges. Mem. Long 
continued soaking in turpentine is apt to render some objects 
brittle, but if cleaning is not very requisite they are not too 
brittle to mount. 
In this way I have treated the polypidoms of Polypi, and as 
these also contain air, I find they require no aid from heat or 
the action of an air-pump, as I have lately seen suggested, 
but merely due time for immersion in a sufficient body of 
turpentine. When the turpentine gets too dirty to do 
this work, it may do daty in grinding holes in the glass 
slides. 
I have found certain animal substances still more re- 
fractory ; as, for instance, the parasite of the Whale, which is 
exceedingly oily, and difficult to purify under the influence of 
turpentine. As a rule, if I find these specimens become 
