CHAPTER XII. 



SOILS. 



§ 1. — THEIR ORIGIN AND NOMEN- 

 CLATURE. 



An intimate knowledge of the nature, and even 

 the nomenclature of soils, is of the utmost im- 

 portance in every branch of cultural science, — to 

 the horticulturist even more so than to the 

 agriculturist, because the subjects under his 

 care are more delicate, and of a much more 

 varied character. The hardier fruit-trees will 

 flourish in soils where the peach, apricot, and 

 vine would refuse to live ; and the same rule 

 holds good amongst many of the productions of 

 the culinary garden. It is, however, in con- 

 nection with the thousands of plants of exotic 

 origin that the nicest distinctions in regard to 

 the nature and nomenclature of soils are called 

 forth ; for certain genera of plants — nay, even 

 certain species of the same genus— require a 

 very opposite soil from those brought from the 

 same locality, ranking in the same natural order, 

 and to all external appearances differing little 

 from them. Those which naturally inhabit a 

 silicious soil will seldom exist long in an argil- 

 laceous one ; and those from peaty soils will not 

 long live in calcareous ones. Seeds of most 

 plants will germinate in a soil composed chiefly 

 of vegetable matter ; but after germination, 

 those whose natural food is derived from an 

 argillaceous soil, will soon linger and die of 

 starvation. 



There is no universal soil, wherein all the 

 productions of a garden can be grown ; while a 

 rich loamy soil may be considered all that is 

 desired by the agriculturist, for in such all his 

 crops will flourish alike. The horticulturist 

 has yearly to collect, from wherever they can 

 be procured, so: ; ls of very opposite characters. 

 To him, therefore, a knowledge of the nature 

 of soils is of paramount importance ; and that 

 knowledge is only to be obtained by one or 

 other of the three tests — which will be after- 

 wards noticed— namely, botanical, chemical, or 

 mechanical. 



Some acquaintance with the nomenclature of 

 soils is to him of equal importance. He may 

 receive plants or seeds from Caffraria, described 

 as having been growing in a silicious soil ; from 

 New Zealand, as having been produced in an 

 argillaceous soil ; from Canada, in a peaty 

 soil; from somewhere else, in a calcareous 



one, and so on. Therefore, without a sufficient 

 knowledge of the difference between these, he 

 would be liable to commit an error of almost 

 daily occurrence, by sowing or planting in a soil 

 perfectly unsuitable for the healthy development 

 of the seed or plant. 



A complete nomenclature of soils is still a 

 desideratum, as was the case in every other de- 

 partment of natural science, until the various 

 specimens in each were reduced to systematic 

 arrangement. At present, the names of soils 

 are scarcely even conventional, nor can it be 

 otherwise until they are subjected to the rules 

 of classification ; and no doubt they will, through 

 the agency of chemistry, be yet arranged into 

 classes, orders, genera, and possibly species and 

 varieties. The only feasible attempt we know 

 of being made in this very important matter is 

 that of M. de Gasparin, which, although far 

 from perfect, is still a step in the right direction. 

 He divides all soils into two classes — namely, 

 inorganic and organic — and this will, we believe, 

 always be recognised as the fundamental prin- 

 ciple of all classification. His subdivisions we 

 do not, however, think sufficiently clear to be 

 of much practical use in their present state. 

 The inquiring reader will find a translation of 

 his arrangement, from the Comptes Rendues de 

 VAcademie des Sciences, in the 27th volume of 

 Jameson's Edinburgh New Philosophical Journal. 



For every practical purpose of cultivation, at 

 least with our present limited knowledge of the 

 subject, soils may be divided into six different 

 classes, and these, we think, will be found to 

 express, sufficiently clear, an idea of the parti- 

 cular soil that is meant. 



These are, argillaceous or clayey, containing 

 above 50 per cent of clay ; silicious or sandy, 

 containing not more than 10 per cent of clay; 

 calcareous or limey, containing more than 20 

 per cent of carbonate of lime ; loamy, having 

 from 20 to 50 per cent of clay; gravelly, com- 

 posed of small stones, silica, a small portion of 

 loam or of clay, and often a considerable per- 

 centage of oxide of iron, particularly in some 

 pit gravels valued for their binding nature, and 

 employed for walk-making, (in alluvial and river 

 gravel this oxide is much less abundant) ; peaty, 

 chiefly formed of vegetable matter, in which a 

 large proportion is in an inert state — most so 

 when it exists in deep masses, surcharged with 



