Injections are more generally employed for the preparation of the eggs of birds, for which it is desirable to secure a long preservation; although by a very bad method, they have also been used for the desiccation of very small animals.
In order to decompose the flesh of a fœtus already formed in an egg, recourse is had to a strong solution of a fixed alkali, of soda, of tartar, or to ether.
Liquors, in which objects are preserved which do not admit of drying.
The qualities which a liquor ought to possess, in which objects of natural history are placed, are, independently of that of preserving from decomposition: 1. to be colourless, that they may not tarnish the contained objects; 2. not to attack by corrosion the proper colours of the object; 3. to be perfectly transparent, that the contained objects may be visible through the vase which encloses them; 4. the power to resist frost, in order that they may not break the jar which holds them.
1. Spirits of wine, of from fourteen to eighteen degrees of the areometer of Baume, appears to be the liquor which best fulfils all these conditions; the other alcohols, such as those from potato, from grain, from sugar, &c., have the same qualities; but a serious inconvenience is the high price of all of them, and this reason alone is an inducement to look for other compound liquors, capable of replacing them with more or less advantage.
2. Nicholas recommends the following composition:
| Very pure water, | 2 ℔. | |
| Alcohol, | 1 ℔. | |
| Sulphate of alumine, | 6 ℥. |
The English naturalist, George Graves, in a work published in London, seven years ago, indicates a liquor which has much analogy with the preceding:
| Alum, | 8 ℥. | |
| Common water, | 1 ℔. | |
| Alcohol, | 1/2 ℔. |