12S BRITISH HUSBANDRY. [Ch. IX. 



are, however, very similar in composition, and are capable of being con- 

 verted into eacli other by a simple chemical process. All the varieties of 

 substances found in plants, are produced from the sap, and the saj) of plants 

 is derived from water, or from the fluids of the soil, and it is attended by, 

 or combined with, principles derived from the atmosphere *." They vary, 

 liowever, in quantity and proportion, not only in the different kinds of 

 grain, but also in tliose of the same species : the temperature of the season, 

 tliR nature of the soil and manure, the degree of maturity which the crop 

 has attained, and the weather at harvest, all give rise to distinct degrees of 

 quality ; and this occasions corn to contain more nutritive properties in 

 some years than in others. 



The weight of ilie different species of graiji varies according to the 

 quality ; but the nutritive properties, though approximating to the weight, 

 yet do not exactly accord with it. The common weights are — 



Of V; heat . . . from 58 to 63 lbs. 



Rye . . . , , 49 , , 56 



Summer Bailey . , , 48 , , 56 



Oats . . . , , 34 , , 42 



It has been lately much recommended to sell corn generally by weight — 

 as at present customary at Liverpool, and some other markets — and a Bill 

 has been brought into Parliament to enforce the practice. This has given 

 rise to much discussion, and we doubt whether, if the measure be carried, 

 it will have any further effect than occasioning some temporary incon- 

 venience to those farmers and dealers who adopt the plan of sale by 

 measure ; for every one must estimate the grain by its general qualities, 

 and no man who understands his business will judge either by weight or 

 measure alone. 



Ft has been calculated by distillers, that certain weights of the vari&us 

 kinds of corn of average quality, produce the following quantities of proof 

 spirits ; namely — 



This proves that the saccharine matter extracted from differeiit species 

 of grain is not exactly in proportion to their respective weights ; but ex- 

 perience has shown that the increase is nearly in the same proportion in 

 those of the same kind. We have, however, already seen, that their nutri- 

 tive properties, however, do not depend wholly on the quantities which they 

 contain of saccharine matter. 



SEED. 



Seed of every kind should attain full maturity ere it be sown ; for, 

 although that which has not arrived at perfection may produce sound 

 crops, when favoured by soil and season, yet there is always considerable 

 risk in employing it. It was formerly, indeed, maintained by the late Sir 

 Joseph Banks, that stunted seed not having lost the faculty of germina- 

 tion, might be sown with entire safety, and the opinion of that eminent 

 naturalist, backed by that of some other writers, brought it for a short 

 time into use. It is, however, evident that, — as the farina, or flour, con- 

 tained in the corn constitutes the food of the embryo plant, until its roots 

 are grown sufticiently large to absorb their own nourishment, — the vege- 



* Lectures on Agvic. Chem., 1st loct. 



