162 SEEDS 



After maceration in water the thin seed-coat is easily separated ; 

 the kernel consists of two, large plano-convex, oily cotyledons, 

 enclosing a small plumule and radicle. The seed is exalbuminous, 

 there being no endosperm. Sweet almonds have a bland nutty taste, 

 and yield, when triturated with water, a white emulsion destitute 

 of any marked odour. The latter character is important, as it is 

 the only definite one by which the sweet almond can be distin- 

 guished from the bitter. 



The student should observe 



(a) The elongated shape (of the Jordan almond), 



(b) The thin seed-coats and two cotyledons without endosperm, 



(c) The bland taste and odour (of the emulsion). 



Constituents. Sweet almonds contain from 40 to 46 per cent, 

 of a bland fixed oil, which can be obtained by pressing the seeds, 

 and about 20 per cent, of proteids, amongst which is included a 

 mixture of enzymes known as emulsin. They contain also a little 

 sucrose, gum, and asparagin. 



Emulsin may be isolated by infusing powdered blanched sweet almonds 

 in water, straining, acidifying with glacial acetic acid, filtering, and precipitating 

 with four volumes of alcohol. It contains lactase, /3-glucosidase, /2-galactosidase, 

 and cellase (cellobiase), and is capable of hydrolysing a large number of (Isevo- 

 rotatory) glucosides. 



Almond oil is pressed both from the sweet and the bitter almond. It consists 

 chiefly of olein accompanied by a small proportion of linolein, &c. ; it is 

 characterised by its specific gravity (0-915 to 0'920), by the quantity of iodine 

 it is capable of combining with (93 to 100 per cent.), by the melting-point of- the 

 mixed fat acids obtainable from it (not over 15), and by the whitish colour 

 when shaken with a cooled mixture of equal parts by weight of sulphuric acid, 

 fuming nitric acid, and water. Drying oils such as cotton seed, &c., combine 

 with larger proportions of iodine ; sesame, ground nut, and certain other oils 

 yield fat acids, melting at a much higher temperature. Apricot kernel oil gives 

 a reddish colour with the nitric acid test. 



Varieties. Jordan (French ' jardin ') almonds, exported from 

 Malaga, constitute the official variety ; they are characterised by 

 their narrow, elongated shape and thin skin. 



Valencia : these are broadly ovoid, shorter, and have a thicker, 

 dusty brown, scurfy coat. 



Sicilian and Barbary : both of these closely resemble the Valencia, 

 but are rather smaller ; they occasionally contain admixtures of 

 bitter almonds. 



East Indian : these are the seeds of the cashew nut Anacardium 

 occidentale, Linne (N.O. Anacardiacece) ; the pericarp of the fruit 

 contains an oily, vesicating liquid, cardol, but the seeds are edible. 



Uses. Sweet almonds are demulcent and nutritive. They are 

 used as a non-starchy food for diabetic patients. 



