38 CALCAREOUS MANURES-THEORY. 



(1818) capable of producing twenty-five or thirty bushels of corn — and the 

 soil well suited to wheat. One thousand grains, cleared by a fine sieve of 

 all coarse shelly matter, (as none can act on the soil until minutely divided,) 

 yielded sixteen ounce measures of carbonic acid gas, which showed the 

 finely divided calcareous earth to be thirty-two grains. 



2. One thousand grains of similar soil from another part of the same 

 field, treated in the same manner, gave twenty-four grains of finely divided 

 calcareous earth. 



3. From the east end of a small island, at the end of Coggins Point, 

 surrounded by the river and tide marsh. Soil, dark brown loam, much 

 lighter than the preceding specimens, though not sandy — under like ex- 

 hausting cultivation — then capable of bringing thirty to thirty-five bushels 

 of corn — not a good wheat soil, ten or twelve bushels being probably a full 

 crop. One thousand grains yielded eight grains of coarse shelly matter, and 

 eighty-two of finely divided calcareous earth. 



4. From a small spot of sandy soil, almost bare of vegetation, and inca- 

 pable of producing any grain, though in the midst of very rich land, and 

 cleared but a few years. Some small fragments of fossil sea-shells being 

 visible, proved this barren spot to be calcareous, which induced its exa- 

 mination. Four hundred grains yielded eighty-seven of calcareous earth 

 — nearly twenty-two per cent. This soil was afterwards dug and carried 

 out as manure. 



5. Black friable loam, from Indian Fields, on York-river. The soil was 

 a specimen of a field of considerable extent, mixed throughout with oyster 

 shells. Though light and mellow, the soil did not appear to be sandy. 

 Rich, durable, and long under exhausting cultivation. 



1260 grains of soil yielded 

 168 — of coarse shelly matter, separated mechanically, 



8 — finely divided calcareous earth. 

 The remaining solid matter, carefully separated, (by agitation and settling 

 in water,) consisted of 

 1 30 grains of fine clay, black with putrescent matter, and which lost more 



than one-fourth of its weight by being exposed to a red heat, 

 875 — white sand, moderately fine, 

 20 — very fine sand, 

 36 — lost in the process. 



1061 



6. Oyster shell soil of the best quality, fi-om the farm of Wills Cowper, 

 Esq., on Nansemond river— never manured, and supposed to have been cul- 

 tivated in corn as often as three years in four, since the first settlement of 

 the country— now yields (by actual measurement) thirty bushels of corn to 

 the acre— but is very unproductive in wheat. A specimen taken from the 

 surface, to the depth of six inches, weighed altogether 



242 dwt., which consisted of 



126 — of shells and their fragments, separated by the sieve, 

 116 — remaining finely divided soil. 

 Of the finely divided part, 500 grains consisted of 



18 grains of carbonate of lime, 

 330 — silicious sand— none very coarse, 



94 — impalpable aluminous and silicious earth, 



35 — putrescent vegetable matter— none coarse or unrotted, 



23 — loss, 



500 



