524 COMPOSITION OF THE TURNIP, CARROT, AND BEET. 



portion of sugar, and of a gelatinous gummy-like substance, to which 

 the name o^ pectin has been given. In the Swedish turnip and in beet- 

 root the sugar ])redominates, in the white turnip and in the carrot tlie 

 pectin is usually present in the larger quantity. 



The composition of the turnip, the carrot, and the beet varies very much, 

 and is influenced by a great variety of circumstances. We are not in 

 possession of any recent detailed analyses of these rootB. The following 

 table exhibits the component parts of several varieties, as they have been 

 given chiefly by Hermbstadt, [Schiibler, Ag. Chem., ii., p. 207] : — 



100 100 100 100 100 100 

 These analyses are very defective, and apply with any degree of cor- 

 rectness only to the specimens actually operated upon. Any reasonings, 

 therefore, which are founded upon them can only lead to probable or ap- 

 proximate conclusions. 



2°. The proportion of sugar contained in the sap of these roots is 

 greatest when they are young, and diminishes as they ripen. In the 

 beet, it has been observed that the nitrates of potash and ammonia are 

 present in considerable quantity, and that in the old beet these nitrates 

 become more abundant as the sugar diminishes. In the beet, also, when 

 raised by the aid of rich manure, the production of nitrates is increased 

 more than that of sugar.* The same may possibly be the case with the 

 common cultivated turnips. It would not be without interest, both theo- 

 retically and practically, to ascertain by experiment, the relative com- 

 position of the same variety of turnip, grown on the same soil, by the 

 aid of rich fann-yard manure, and by the aid of bones or of rape-dust. 

 The one may produce more sugar, the other more albumen or nitrates. 

 Such differences may materially affect the value of the crop, either in 

 the feeding of stock or in the production of an enriching manure. It is 

 in suggesting and carrying on enquiries of this kind that the joint labours 

 of the practical farmer and of the theoretical chemist are likely, among 

 other ways, to promote the advancement of a rational and scientific agri- 

 culture. 



3°. Effect of soils and manures. — These roots delight in a rich, open, 

 and loamy soil — and the weight of produce varies much with the kind 

 of manure that may have been applied to them. [See, for many in- 

 structive illustrations of this fact, the experiments upon turnips, detailed 

 in the Appendix, pp. 43 et seq.] No experiments, however, have yet 

 been made to determine the relative proportions of water and of their 

 other constituents which the same turnips contain, when raised by the 



* According to Payen, the beet, w*ien raised with street manure, contains 20 times a* 

 mucb saltpetre as when raised in the ordinary manner. 



