“Any species of animal being given, to preserve it the most certainly, the most perfectly, and with the smallest quantity of an alcoholic liquid of the least possible strength.”
Alcohol is very costly in this country, where considerable duties are exacted, nor is it suitable for preserving bodies, except of small volume. During voyages, this liquor is difficult of export, evaporates rapidly, particularly in equatorial regions, and often bursting the vessels which contain it; it alters or dissolves the resins or resinous mastic which is used to seal the jars or other vessels which contain the animals.
If an acid be added to alcohol, the bones are acted upon, and softened; colours are destroyed; the scalpels and other dissecting instruments are promptly oxidised, when it is desirable to dissect animals preserved in these liquors.
The same inconveniences exist if alcohol holds arsenic in solution, or corrosive sublimate, and many other metallic salts.
The essence of turpentine can only serve for small pieces; it is not easily transported, alters several of the tissues, becomes thick and clouded.
The oils are suitable only for the preservation of some fishes; their acquisition is expensive, and it is difficult to obtain them everywhere.
The syrups which have been proposed for the preservation of some animal parts, such as the brain, spinal marrow, &c., are too dear to be useful to any great extent; besides, they do not penetrate the tissues profoundly, preserve only the external surfaces, deposit crystals or a viscous matter which changes the colour; and, finally, they run readily into fermentation, especially in hot climates.
Creosote, advised of late, for the preservation of the nerves and brain, is too costly, but, as we have not made use of it, we cannot describe its mode of action upon the tissues.
Sea-salt, employed alone and in solution, has a mode of action for a long time known, and its inefficiency cannot be disputed; we do not speak however, of saltings, because this method cannot answer for the preservation of bodies for dissection; or for preserving animals from putrefaction, that they may be subsequently dissected, or be placed in zoological collections.
In an English Medical Journal, for the year 1818, we find, that it is proposed to replace alcohol by rock-salt, for the preservation of anatomical and natural history subjects, which is known to be nothing more than muriate of soda, purer than that of commerce; this proposition is inadmissible.