M. Geoffroy prepares the Sedative Salt by crystallization only, in the following manner. "He dissolves four ounces of refined Borax in a sufficient quantity of warm water, and then pours into the solution one ounce and two drams of highly concentrated Oil of Vitriol, which makes a crackling noise as it falls in. When this mixture has stood evaporating for some time, the Sedative Salt begins to make its appearance in little, fine, shining plates floating on the surface of the liquor. The evaporation is then to be stopped, and the plates will by little and little increase in thickness and breadth. They unite together into little tufts, forming with each other sundry different groups. If the vessel be ever so little stirred, the regularity of the crystals will be disturbed; so that it must not be touched till the crystallization appears to be finished. The crystalline clusters, being grown too bulky and too heavy, will then fall of themselves to the bottom of the vessel. This being observed, the saline liquor must be gently decanted from those little crystals, which, as they are not easily dissolved, must be washed clean, by pouring cold water slowly on the sides of the pan, three or four times successively, in order to rinse out all remains of the saline liquor, and then set first to drain, and afterwards to dry in the sun. This Salt, in the form of light flakes of snow, is now soft to the touch, cool in the mouth, slightly bitter, crackling a little between the teeth, and leaving a small impression of acidity on the tongue. It will keep long without giving or calcining, if managed according to the preceding directions; that is, if it be exactly freed from its saline liquor. "It differs from the Sedative Salt obtained by sublimation in this respect only, that notwithstanding its seeming lightness it is a little heavier than the other. M. Geoffroy supposes the cause of this weight to be, that, as several of the thin plates adhere together in crystallizing, they retain between them some small matter of humidity; or, if you will, that, as they form larger crystals, they present less surface to the air which elevates light bodies: whereas, on the contrary, the other Sedative Salt, being driven up by the force of fire, rises into the head of the cucurbit in a more subtile form, having its particles much more expanded and divided.