366 



SECTION VI. 



Note I. Page 160. 



According to Bergman, the soil best adapted to culture consists of 

 4-lOths of clay, 3-lOths sand, 2-lOths calcareous earth, and 1-lOth mag- 

 nesia. Fourcroy and Hassenfratz found 9216 parts of fertile soil to contain 

 305 parts of carbon, together with 279 parts of oil ; of which, according 

 to the calculations of Lavoisier, 220 parts may be considered as car- 

 bon ; so that the whole of the carbon contained in the oil may be esti- 

 mated at nearly 525 parts, not reckoning the roots of vegetables, or about 

 l-16th part of its weight. Young, a scientific agriculturist, observed, 

 that equal weights of different soils, when dried and reduced to powder 

 yielded by distillation quantities of air, in some measure corresponding 

 with the ratio of their values. The air was a mixture of fixed and in- 

 flammable air, proceeding probably from the decomposition of the 

 water, but partly also, as may be supposed, from its power of abstract- 

 ing a quantity of air from the atmosphere, which the soil is likewise 

 capable of doing. 



One of the most favourable soils in England, for the production of 

 fine wood, is said to be Sheffield-place, the seat of Lord Sheffield. 

 " What is most remarkable (as Pontey observes) is, that the oak and 

 the larch flourish equally upon it ; though it would seem too light for 

 the former, and too stiff for the latter." — Profitable Planter, p. 106. 

 In order to ascertain the constituent parts of a soil so celebrated for the 

 production of timber. Sir Humphrey Davy submitted one hundred parts 

 of the entire soil to analysis, of which the following was the result : 



Water 3 



Silex 54 



Alumine 28 



Carbonate of Lime 3 



Oxide of Iron 5 



Decomposing Vegetable matter 4 



Loss 3 



100 parts. 

 This, no doubt, is a very favourable statp of rompnnent parts ; nltliougli 



