In the original, four ounces of lime is recommended, and we have given this dose in our first edition; but it has since been found by doubling it, the preservative is less pasty, and less difficult to use, more abundant and equally good. M. Simon thus composes the preservative, but he adds to it a certain quantity of corrosive sublimate, and of camphor dissolved in spirits of wine. The camphor, thus incorporated with the preservative, does not volatilize so easily as when used in powder. When used, a sufficient quantity is placed in a small vessel, and, with the aid of a hair pencil, it is moistened with water and spread upon the piece to be preserved. Some naturalists, fearful of the danger of the daily use of arsenic, have endeavoured to replace this preservative by another composition, but have never succeeded in obtaining results equally advantageous; but, nevertheless, in order to render this work as complete as possible, and to facilitate new researches, we thought that we should at least, indicate here, the different processes which have by turns been imagined. In my cabinet of natural history, I have indicated, under the name of _soapy pomatum_, the following composition: ℞. White soap, 1 ℔. Potash, 1/2 ℔. Powdered alum, 4 ℥. Common water, 2 ℔. Oil of petroleum, 4 ℥. Camphor, 4 ℥. M. Mouton de Fontenille proposes a tanning liquor thus composed: ℞. Quinquina, 1 ℥. Grenada bark, 1 ℥. Oak bark, 1 ℥. Gentian root, 1 ℥. Absynthium, 1 ℥. Tobacco, 1 ℥. Powdered alum, 1 ℥. Common water, 2 ℔. Boil the whole, except the alum, which is not to be added to the liquor until withdrawn from the fire; it is to be put into a well corked vial for use. M. Mouton thus uses his liquor: when an animal is skinned, and the skin divested of grease as well as possible, the internal surface is to be moistened with the tanning liquor until it is perfectly impregnated; if it be a dry skin, it is to be moistened in the same manner until it is softened. An author has recommended, under the name of _antiseptic powder_, the following composition: ℞. Arsenic, 1 ℔. Calcined alum, 1-1/2 ℔. Purified sea salt, 1/2 ℔. The whole to be reduced to a fine powder and well mixed. We advise that powdered arsenic never be used, because, by volatilizing, it might penetrate the lungs and cause mortal ravages.[N]