CRUCIFEROUS PLANTS. 173 



membranous ; petals of corolla, erect, ovate, blue, with dark keel ; 

 bulbs oblong. 



ROCAMBOLE, allium scorodoprasum. C. 6. O. 1. Br. P. 2 ft. A 

 species of the garlic, and a native of the N. of Europe. It is distin- 

 guished for its mild and fine flavor. It has narrow flat leaves, wilh a 

 keel or ridge on the under side. The head is contorted, but untwists 

 on maturity, and presents a cluster of small bulbules of a purplish 

 tinge. It is propagated by the cloves from the root, or the top of the 

 stalk, which are larger, but less pungent. The plant holds an in- 

 termediate space between the garlic and shallot. The bulbs are smal- 

 ler than those of the garlic ; they are heart-shaped ; and those, both 

 of the top and bottom are used for the same purposes, but the former 

 are more delicate. They are also planted in the same way, in Oct. 

 or Nov. The richer the ground, the more cloves are produced. 



The composition of the edible alliaceous plants we have just con- 

 cluded is nearly alike in the various species and varieties, as stated 

 under garlic and onion. Their volatile oil, constituting their acrid 

 and stimulating qualities, being dissipated by cooking, they form a 

 mild and easily disgestible food. 



CRUCIFEROUS PLANTS. 



These are a class of plants which do not afford the nutritive princi- 

 ple sugar, farina, or starch ; but they are, nevertheless, important ar- 

 ticles of food. . It is certain that the human system requires a propor- 

 tion of herbaceous vegetable matter to preserve health, and that none 

 supply this in a more efficient form than this order of plants. These 

 differ from most others in containing more nitrogen, a well known and 

 essential element of animals ; and it is further remarkable that all 

 plants of this order are innocent if not always nutritive. Although 

 they do not possess the principles above-mentioned, it is probable that, 

 in the process of assimilation they are quite as important as those 

 which do, especially in furnishing the body with the important ele- 

 ment nitrogen. 



This order of plants embraces the Cabbage and its numerous varie- 

 ties of Brocoli, Cauliflower, Sprouts, &c. ; also the Turnip, Sea-kail, 

 Radish, Cress, Mustard, &c., some of which we have arranged under 

 the general head of esculent roots, salads, &c. The plants of this order 

 derive their nutritive properties from their mucilaginous, saccharine 

 and extractive matter ; and, with one or two doubtful exceptions, no 

 cruciferous plants are poisonous. In most varieties of the braccia, 

 or cabbase tribe, the parts used are the leaves. They are composed 

 chiefly of water, with small portions of acids or salts. 90 per cent, of 

 these are given off by drying. The remaining parts in the 100 are 

 15* 



