SOILS, CHARACTER OF. 476 SOILS, CHEMICAL ANALYSIS. 



stance, which combines with atmospheric 

 oxygen, giving rise to phosphoric acid, 

 which enters into the composition of all 

 our cultivated plants, and is essentially 

 necessary to a healthy condition of vege- 

 table life. It exists in trap-rock, granite, 

 basalt, and other igneous rocks, and in 

 lime, ironstone, and most minerals. 



CHLORINE. This is a highly noxious, 

 suffocating, yellowish, gaseous element, 

 particularly disagreeable in smell. In 

 soils it is found in combination with such 

 bases as chloride of sodium, or common 

 salt. It is more necessary as a plant food 

 to root crops than to cereals. 



Prevailing Substances in Soils. Soils, 

 then to sum up briefly that which has 

 been stated in fuller terms above may be 

 said to consist of a mechanical mixture of 

 four substances (i) Silica, silicious sand, 

 or gravel ; (2) Clay ; (3) Lime ; and (4) 

 Humus, with many of the chemical sub- 

 stances above mentioned, in varying 

 proportions. Hazel loam, brown loam, 

 clayey loam, fat soil, sandy soil, garden 

 mould, which are continually spoken of by 

 the gardener, have no specific proportions 

 in themselves, but, nevertheless, on those 

 proportions their fertility and capabilities 

 depend. 



Soils, Sandy. These are loose, friable, 

 open, and dry, and for that reason easily 

 cultivated. They rest chiefly on the old 

 led sandstone, and granite and coal for- 

 mations. When alumina and calcareous 

 matter are absent, however, they are 

 nearly barren : they absorb manures 

 without benefit to the land. Where 

 alumina and lime exist they are more 

 compact and adhesive, and grow good 

 crops of beans, peas, spring wheat, and 

 turnips. They are capable of improve- 

 ment by admixture with clay, marl, chalk, 

 and other adhesive soils, which communi- 

 cate their constituent properties to them. 



Soils, Calcareous. Soils of this kind 



that rest on the upper chalk formation aie 

 usually deep, dry, loose, friable, and fertile 

 in their nature ; but others, resting on the 

 shaly oolite, are stony, poor, thin soils. 

 Leguminous plants, as peas, beans, 

 vetches, sainfoin, and clover, do well on 

 such soils, lime being essential to their 

 growth. Where pure clay is present in 

 such soils, they are called loams or cal- 

 careous clays ; where silica is in excess, 

 they are termed calcareous sandy soils. 



Soils, Clay. These are characterised by 

 stiffness, impenetrability, great power of 

 absorbing and retaining moisture, and 

 great specific gravity ; they are conse- 

 quently, cold, stiff, heavy, and impervious, 

 costly to cultivate, and often unproductive. 

 Perfect drainage, burning the soil with 

 wood faggots, branches of trees, grass 

 sods, and vegetable refuse, and mixing 

 chalk and sand, are the only remedies. 

 Burning is the most efficient remedy ; the 

 burnt clay acting chemically as a manure, 

 its constituents being rendered more 

 soluble. Provided a moderate heat has 

 been applied to the process, the potash 

 is rendered soluble, and liberated from the 

 clay in which it occurs in an insoluble 

 combination. Thus treated, clay soils 

 become the most fertile for all heavy 

 crops. 



Soils, Chemical Analysis of. 



It will be obvious to the reader that the 

 process of analysis involves more minute- 

 ness of detail in carrying it out than it is 

 possible to enter into here. Those who 

 desire full and exhaustive information on 

 the subject are referred to " The Handy 

 Book of the Chemistry of Soils," by Dr. 

 Scoffern, " The Elements of Agricultural 

 Chemistry and Geology," by the late Pro- 

 fessor Johnson and Dr. Cameron, and 

 Professor Johnston's "Instructions for the 

 Analysis of Soils." These books arc 

 eminently practical, and eniei into all 



