301 PLANTS PECULIAR TO CERTAIN SOILS. 



2° Chemical methods, including llmeing, marling, and the application 

 of vegetable, animal, and mineral manures. 



To satisfy you fully, however, in regard to the absolute necessity 

 for such changes, if we would render the land fit to produce any given 

 crop, let me illustrate, by a few brief examples, the intimate relation 

 observed in nature between the kind of soil and the kind of plants that 

 grow upon it. 



§ 1. 0« the connection between the kind of soil and the land of plants 

 that grow uj)on it. 



That a general connection exists between the kind of soil and the 

 kind of plants that grow upon it, is familiar to all practical men. Thus 

 clay soils are generally acknowledged to be best adapted for wheat — 

 loamy soils for barley — sandy loams for oals or barley — such as are more 

 sandy s^ll for oats or rye — and those which are almost pure sand, for 

 rye alone of all the corn-bearing crops. 



But in a state of nature, we find special differences among the spon- 

 taneous produce of the soil, which are more or less readily traceable to 

 its cheruical constitution in the spots where the plants are seen to 

 grow. Thus — 



1°. On the sandy soils of the sea shores, and oh the salt steppes ol 

 Hungary and Russia, the sand- worts, salt- worts, glass-worts, and other 

 salt-loving plants abound. When these sands are inclosed and drained, 

 the excess of the salt is gradually washed out by the rains, or in some 

 countries is removed by reaping the saline plants annually, and burning 

 them for soda (barilla), when wholesome and nutritive grasses take their 

 place ; but the white clover and the daisy, and the dandelion, must first 

 appear, before, as a general rule, it can be profitably ploughed up and 

 sown with corn. 



2°. The dry drifted sands, more or less remote from the sea, produce 

 no such plants. They are distinguished by their own coarse grasses, 

 among which the clymus arenarius (upright sea lyme-grass) often, in our 

 latitudes, occupies a conspicuous place. On the downs of North Jut- 

 land, it was formerly almost the orly plant which the traveller could 

 meet with over an area of many nl es. 



3°. On ordinary sandy soils, legummous plants are rare, and the herb- 

 age often scanty and void of nourishment. With the presence of marl 

 in such soils, the natural growth of leguminous plants increases. The 

 colt's-foot also, and the butter-bur, not only grow naturally where the 

 subsoil is marly, but infest it sometimes to such a degree as to be with 

 great difficulty extirpated. So true is this indication of the nature of 

 the soil, that in the lower vallies of Switzerland these plants are said to 

 indicate to the natives where they may successfully dig for marl, (Prize 

 Essays of the Highland Society, I., p. 134). On calcareous soils, again, 

 or such as abound in lime, the quicken or couch-grass is seldom seen as 

 a weed, (Sprengel, Bodenkunde, p. 201 ), while the poppy, the vetch, and 

 the darnel abound. 



4°. So peaty soils, when laid down to grass, slowly select for them- 

 selves a peculiar tribe of grasses, especially suited to their own nature, 

 among which the holcus lanatus (meadow soft-grass) is remarkably 

 abundant. Alter their constitution by heavy limeing, and they produce 



