SWEET ALMOND 297 



AMYGDALA DTJLCIS. Sweet Almond. The ripe seeds of Prunus 

 Amygdalus dulcis (Fam. Rosacese), a tree like the bitter almond 

 but more extensively cultivated. The commercial supply is obtained 

 from northern Africa, southern France, Italy and Spain, the choicest 

 seeds being imported from Malaga and known as " Jordan almonds." 



Description. Closely resembling the Bitter Almond, but giving 

 no odor of hydrocyanic acid when treated with water, or of benzal- 

 dehyde when old ; taste bland and sweet. 



Inner Structure. (Fig. 132.) In both bitter almonds and sweet 

 almonds the outer epidermal layer of the seed-coat is composed of 

 characteristic, rectangular, somewhat rounded stone cells. The 

 latter are from 0.070 to 0.175 mm. in length and from 0.065 to 0.100 

 mm. in width; the walls are from 0.010 to 0.015 mm. in thickness 

 and have numerous simple pores. The seed-coat also contains 

 tracheae with spiral thickenings, associated with which are cells con- 

 taining rosette aggregates or prismatic crystals of calcium oxalate 

 that are about 0.007 mm. in diameter. The endosperm consists of 

 a single layer of nearly cubical cells about 0.015 mm. in diameter. 

 The cells of the embryo contain numerous aleurone grains, which are 

 from 0.005 to 0.015 mm. in diameter and consist of crystalloids, 

 globoids and calcium oxalate. 



Powder. Usually ' sold under the name of Almond Meal and 

 consists chiefly of the tissues of the embryo. It is yellowish-white 

 in color and contains numerous fragments of parenchyma, contain- 

 ing oil globules and aleurone grains; also occasional fragments of 

 seed-coat with characteristic, more or less scattered, large elliptical, 

 thin-walled, strongly lignified epidermal cells and narrow, closely 

 spiral tracheae; numerous separated oil globules of different sizes 

 and crystalloids, the latter occasionally with adhering globoids; 

 few or no starch grains should be present. The so-called almond 

 meal, which is used as a cleansing agent, consists of almond cake, 

 a by-product in the manufacture of almond oil, to which are added 

 other substances to give it a pleasant odor, as orris root (Fig. 47). 

 A spurious almond meal consists of wheat middlings (Fig. 21) to 

 which powdered soap and sufficient volatile oil or triple extract are 

 added to perfume it. 



Constituents. Resembling bitter almond, but containing slightly 

 more fixed oil (about 50 per cent), and being free from amygdalin. 



Substitutes. The seeds of other plants of the Rosaceae are some- 

 times substituted for almond seeds. These usually have a bitter 

 and more or less disagreeable taste; the outer epidermal cells in 

 apricot and plum being tangentially elongated, while those of peach 



