MANUAL OF AGRICULTURE. 



26a 



portions of the stems and leaves of plants. It is supposed there 

 to serve as a defence to the plant against external injury, and to 

 give strength to the stem in the case of the grasses and corii- 

 yielding plants ; but what chemical functions it performs, if any, 

 in directly promoting vegetable growth, we can scarcely as yet 

 even venture to guess." 



The following analysis of a good arable light sandy loam by 

 Anderson will give an idea of the manner in which the several 

 elements are combined in the soil, although the several salts are 

 broken up into their component acids and bases : — 







10,000-00 



Soils. 



From the difficulties which attend the obtaining of complete 

 analyses of soils, no large amount of attention has hitherto 

 been devoted to this branch of agricultural chemistry, except in 

 instances where the object has been to determine the quality of 

 some of the more important and indispensable constituents, such 

 as lime. It will easily be granted, what a variety the analyses 

 of different soils must present. The width of variation musti 

 he obvious, which exists between the composition of the soil 

 of a chalky district and of soil taken from a reclaimed peat- 

 moss. And again, whilst the analyses of two soils may show 

 an almost identical composition, their measure of fertility may 

 still be very unequal, owing probably to the soluble nature of 

 the components of the one, and the different conditions of com- 

 bination, and lessened degree of solubility 2)revailing with the 

 constituents of the other. 



In connection with the analysis last above given, the following 

 table, extracted from Stephens's " I'ook of the Farm," give the 

 amount of ash or inorganic material taken from the soil by some 

 of our cultivated plants — the (piantity being for every 100 Iba. of 

 each plant : — 



