CALCAREOUS MANURES-THEORY. 33 



racter to the soils of the United States, without expressing a doubt ov 

 naming an exception. These writers, as all who have heretofore written 

 of soils in this country, have uttered but the echoes of preceding English 

 general descriptions of soils. They seem not to have suspected that any 

 very important dilTerence existed in this respect between the soils of Eng- 

 land and of this country, and certainly not one had made the slightest in- 

 vestigation by any attempt at chemical analysis, to sustain the false charac- 

 ter thus given to our soils. 



1. From a " Treatise on Agriculture," (ascribed to General Armstrong,) 

 published in the American Farmer. [Fo/. i. page 153.] 



» Of six or eight substances, which chemists have denominated earths, 

 four are widely and abundantly diffused, and form the crust of our globe. 

 These are silica, alumina, lime, and magnesia." — "In a pure or isolated 

 state, these earths are wholly unproductive; but when decomposed and 

 mixed, and to this mixture is added the residuum of dead animal or vege- 

 table matter, they become fertile, and take the general name of soils, and 

 are again denominated after the earth that most abounds in their composi- 

 tion respectively." 



2. Address of R. H. Rose to the Agricultural Society of Susquehanna. 

 [Am. Far. Vol. ii. p. 101.] 



"Geologists suppose our earth to have been masses of rock of various 

 kinds, but principally silicious, aluminous, calcareous, and magnesian-from 

 the gradual attrition, decay, and mixture of which, together with an addi- 

 tion of vegetable and animal matter, is formed the soil ; and this is called 

 sandy, clayey, calcareous, or magnesian, according as the particular primi- 

 tive material preponderates in its formation." 



3. Address of Robert Smith to the Maryland Agricultural Society. [_Am. 

 Far. Vol. Hi. p. 228.] 



« The soils of our country are in general clay, sand, gravel, clayey 



loam, sandy loam, and gravelly loam. Clay, sand, and gravel, need no de- 

 sci-iption, ^.c:'— "■Clayey loam is a compound soil, consisting of clay and 

 sand or gravel, with a mixture of calcareous matter, and in whicli clay is 

 predominant, Sandy or gravelly loam is a compound soil, consisting of 

 sand or gravel and clay with a mixture of calcareous matter, and in which 

 sand or gravel is predominant." 



The first two extracts merely state the geological theory of the forma- 

 tion of soils, which is received as correct by the most eminent agriculturists 

 of Europe. How far it may be supported or opposed by the actual consti- 

 tution and number of ingredients of European soils, is not for me to decide, 

 nor is the consideration necessary to my subject. But the adoption of this 

 general theory by American writers, without excepting American soils, is 

 an indirect, but complete application to them of the same character and 

 composition. The writer last quoted states positively, that the various 

 loams (which comprise at least nineteen twentieths of our soils, and I pre- 

 sume also of the soils of Maryland,) contain calcareous matter. The ex- 

 pression of this opinion by Mr, Smith is sufficient to prove that such was 

 the fair and plain deduction from his general reading on agriculture, from 

 which source only could his opinions have been derived. If the soils of 

 Maryland are not very unlike those of Virginia, I will venture to assert, 

 that not one in a thousand of all the clayey, sandy, and gravelly loams, 

 contains the smallest proportion of carbonate of lirne— and that not a single 

 specimen of calcareous soil can be found, between the falls of the rivers 

 and the most eastern body of limestone. 



But though the direct testimony of European authors, as cited in a 

 foregoing page, concurs with the indirect proofs referred to since to induce 

 the belief that soils are very rarely destitute of calcareous earth, yet state- 



