UO ELEMENTAEY AGRICULTUHAL CHEMISTRY 



a fleshy pulp (the edible portion), the whole being covered 

 with a thin skin. The kernel, and in some cases the bark and 

 leaves, contains a glucoside known as amygdalin, CgoHgyNOn, 

 which under the influence of an enzyme — emulsin — generally 

 present in the kernel, decomposes in the presence of water, 

 thus : 



C,,H,,NO„ + 2Hp = CJI.CIIO + HON + 2C,H,,0„ 



the products being benzaldehyde, hydrocyanic or prussic acid» 

 and glucose. The flesh of all fruits of the plum family is 

 rich in sugar and faintly acid with various organic acids, of 

 which malic {Kfififi^ and citric acid (HgCgH^Oy) are the 

 principal. 



The following are partial analyses of the fruits : 



Citrus Fruits. — The chief varieties are the orange, the 

 lemon, the lime, the citron, and the shaddock or pompelmous. 

 All members of this family thrive only in warm climates. 

 Frost is very liable to cause death to the trees. They do best 

 in rich, deep, mellow soil, with porous subsoil. The fruits 

 contain sugar, citric acid, and comparatively small quantities 

 of cellulose and ash constituents, while the rind contains 

 considerable quantities of essential oils. 



