This perfume has been much esteemed for many ages.  It may be procured by distilling the leaves of any of the laurel tribe, and the kernels of stone fruit; for trade purposes, it is obtained from the bitter almonds, and exists in the skin or pellicle that covers the seed after it is shelled.  In the ordinary way, the almonds are put into the press for the purpose of obtaining the mild or fat oil from the nut; the cake which is left after this process is then mixed with salt and water, and allowed to remain together for about twenty-four hours prior to distillation.  The reason for moistening the cake is well understood to the practical chemist, and although we are not treating the subject of perfumery in a chemical sense, but only in a practical way, it may not be inappropriate here to observe, that the essential oil of almonds does not exist ready formed to any extent in the nut, but that it is produced by a species of fermentation, from the amygdalin and emulsine contained in the almonds, together with the water that is added.  Analogous substances exist in laurel leaves, and hence the same course is to be pursued when they are distilled.  Some manufacturers put the moistened cake into a bag of coarse cloth, or spread it upon a sieve, and then force the stream through it; in either case, the essential oil of the almond rises with the watery vapor, and is condensed in the still-worm.  In this concentrated form, the odor of almonds is far from agreeable; but when diluted with spirit, in the proportion of about one and a half ounce of the oil to a gallon of spirit or alcohol, it is very pleasant.

[Illustration:  Almond.]

The essential oil of almonds, enters into combination with soap, cold cream, and many other materials prepared by the perfumer; for which see their respective titles.

Fourteen pounds of the cake yield about one ounce of essential oil.

In experiments with this substance, it must be carefully remembered that it is exceedingly poisonous, and, therefore, great caution is necessary in its admixture with substances used as a cosmetic, otherwise dangerous results may ensue.

Artificial Otto of Almonds.—­Five or six years ago, Mr. Mansfield, of Weybridge, took out a patent for the manufacture of otto of almonds from benzole. (Benzole is obtained from tar oil.) His apparatus, according to the Report of the juries of the 1851 Exhibition, consists of a large glass tube in the form of a coil, which at the upper end divides into two tubes; each of which is provided with a funnel.  A stream of nitric acid flows slowly into one of the funnels, and benzole into the other.  The two substances meet at the point of union of the tubes, and a combination ensues with the evolution of heat.  As the newly formed compound flows down through the coil it becomes cool, and is collected at the lower extremity; it then requires to be washed with water, and lastly with a dilute solution of carbonate of soda, to render it fit for