The condenser consists of a series of pipes of block tin, either immersed in tanks of cold water or over which cold water is kept running, the condenser being connected with the top of the distilling vats. The condensed steam, together with the oil, flows into a metallic receiver, in which the oil, being lighter than the water, rises to the top and can be drawn off. The perforated false bottoms with which the vats are supplied permit the passage of steam. A strong iron hoop is placed about this false bottom, and two pairs of stout chains, which meet at the top of the vat in a pair of rings, are attached to it. After the charge has been distilled it is drawn from the vats by means of this arrangement. The plants are thrown into the vats and are closely packed by two or three men tramping upon them, and as the vat becomes about one-third full the packing is still further assisted by turning in a small supply of steam, which softens the plants. When the vat is filled the tight cover is replaced and a full head of steam turned on. In the largest distilleries the vats have a capacity of from 2,000 to 3,000 pounds of dried plants each. [Illustration: FIG. 3.—Peppermint still. (After Dewey, in Bailey’s Cyclopedia of American Horticulture.) _A_, boiler; _B_, steam pipes leading to vats; _C_, valves for shutting off steam; _D_, mint packed in vat ready for distilling; _E_, mint being lowered into vat; _F_, tight-fitting cover used alternately for both vats; _G_, pipe from top of vat, joined at _H_ so as to swing to other vat; _J_, perforated pipe, from which cold water drops over condensing tubes; _K_, supply pipe for cold water; _M_, condensing pipes; _N_, outlet for condensed oil and water; _O_ and _P_, water and oil in separating can; _R_, outlet for water; _S_, floor of distilling room.] Large tanks are used for storing the oil, and cans holding 20 pounds each are employed for shipping, three of these cans being placed in a wooden case. The peppermint hay which remains after distillation is used as a fertilizer or is fed to stock. PEPPERMINT OIL AND MENTHOL. Peppermint leaves and flowering tops are official in the Eighth Decennial Revision of the United States Pharmacopœia, as are likewise the following products and preparations derived from these parts: Oil of peppermint, menthol, spirit of peppermint, and peppermint water.