This is the preservative employed in the museum and its success is certain. It is well to use it especially for rare and precious specimens, about whose preservation there is any cause of anxiety. It is wise to plaster the skins of birds with it, especially the claws and bill. It is well, likewise, to plaster the naked parts of quadrupeds, such as the face and hands of apes. Each bird or quadruped of small or middling size, thus prepared, and in the inside of which a little cotton is put, not to give it a form, but that the different parts of the skin need not touch, should be placed in a sack or enveloped in paper well closed, and these sacks should be ranged in a box, which should be well pointed, so that not only dampness but even air may be excluded. The skins of large animals, too thick to be preserved by means of arsenical soap, should be rubbed whith salt. The skin of the animal should be stretched, covered carefully with salt within and without, and when, after several days it is sufficiently saturated, it should be folded with the epiderm inside, and put in a box, or simply wrapped in cloth, straw or any other dry substance, and keept as much as possible beyond the reach of dampness. The means that we have pointed out are simple, easy and require little time. We come now to the way of preserving animals in alcohol. If they are quadrupeds, birds, reptiles or fish of considerable size, each specimen should be wrapped in linen tied round the body with thread; if the animals are very small like mice, small vipers, shell-fish or worms, the linen should be large; a certain number of these animals are placed upon it so that they do not touch; then the linen is rolled upon it self, so as to make a doll sowed with thread, that it may not unwind; afterwards, place the bundles side by side in a cask. When the cask is full, so that the bundles are packed close, it should be filled with brandy, rum or whiskey; generally some strong liquor; afterwards it should be pitched with care, so that the liquor may not escape. This method has two advantages: 1º animals wrapped in linen cannot tear each other with their nails or spines; 2º the linen having imbibed the alcohol, if the cask leakes, the animal will not be entirely dry; and when the casks are opened, as they should be several times on a long voyage, there be an opportunity of filling them again with alcohol. The spirituous liquor be from 16 to 22 deg. of the areometer of Baume; stronger, it destroys the colors of animals; it is used at 22 deg. only for mammifers. All spirituous liquor are equally good. The color less are preferable. Before wrapping vertebrated animals in cloth, an incision should be made in the breast and abdomen, to let the liquor run in the inside of the body. The opening should be very small, in the side, and not in the middle. If the mammifers are large, it is well to pour the alchool in the intestinal canal, either by the mouth or anus.