The oil (Oleum Amygdalæ) is a thin, light yellow fluid, of sp. gr. 0·92, which does not solidify till cooled to between -10 and-20° C. When fresh, it has a mild nutty taste, but soon becomes rancid by exposure to the air; it is not, however, one of the drying oils. It consists almost wholly of the glycerin compound of Oleic Acid, C₁₈H₃₄O₂.
Almonds easily yield to cold water a sugar tasting like honey, which reduces alkaline cupric tartrate even in the cold, and is therefore in part grape sugar. Pelouze however (1855) obtained from almonds 10 per cent. of cane-sugar. The amount of gum appears to be very small; Fleury (1865) found that the total amount of sugar, dextrin and mucilage was altogether only 6·29 per cent.
If almonds are kept for several days in alcohol, crystals of asparagine ([see article Rad. Althææ, p. 93]) make their appearance, as shown by Henschen (1872), and by Portes (1876).
The almond yields 3·7 per cent. of nitrogen, corresponding to about 24 per cent. of albuminoid matters. These have been elaborately examined by Robiquet (1837-38), Ortloff (1846), Bull (1849), and Ritthausen (1872).[950] The experiments tend to show that there exist in the almond two different protein substances; Robiquet termed one of these bodies Synaptase, while others applied to it the name Emulsin.[951] Commaille (1866) named the second albuminous substance Amandin; it is the Almond-legumin of Gmelin’s Chemistry, the Conglutin of Ritthausen. Emulsin has not yet been freed from earthly phosphates which, when it is precipitated by alcohol from any aqueous solution, often amount to a third of its weight. Amandin may be precipitated from its aqueous solution by acetic acid. According to Ritthausen, these bodies are to be regarded as modifications of one and the same substance, namely vegetable casein.
Blanched almonds comminuted yield, when slightly warmed with dilute potash, a small quantity of hydrocyanic acid and of ammonia; the former may be made manifest by means of Schönbein’s test pointed out at [p. 250].
The ash of almonds, amounting to from 3 to nearly 5 per cent., consists chiefly of phosphates of potassium, magnesium and calcium.
Production and Commerce—The quantity of almonds imported into the United Kingdom in 1872 was 70,270 cwt., valued at £204,592. Of this quantity, Morocco supplied 33,500 cwt., and Spam with the Canary Islands 22,000 cwt., the remainder being made up by Italy, Portugal, France, and other countries. The imports into the United Kingdom in 1876 were 77,169 cwt., valued at £244,078. Almonds are largely shipped from the Persian Gulf: in the year 1872-73, there were imported thence into Bombay, 15,878 cwt., besides 3,049 cwt. from other countries.[952]
Uses—Sweet almonds may be used for the extraction of almond oil, yet they are but rarely so employed (at least in England) on account of the inferior value of the residual cake. The only other use of the sweet almond in medicine is for making the emulsion called Mistura Amygdalæ.
AMYGDALÆ AMARÆ.
Bitter Almonds; F. Amandes amères; G. Bittere Mandeln.