the mould covering the surface of the earth, in which vegetables grow. It serves as a support for vegetables, and as a reservoir for receiving and communicating nourishment.

Soils are commonly double or triple compounds of the several reputed primitive earths, except the barytic. The magnesian likewise sparingly occurs. The more fertile soils afford also a small proportion of coaly substances arising from putrefaction, and some traces of marine acid and gypsum. The vulgar division into clay, chalk, sand, and gravel, is well understood. Loam denotes any soil moderately adhesive; and, according to the ingredient that predominates, it receives the epithets of clayey, chalky, sandy, or gravelly. The intimate mixture of clay with the oxides of iron is called till, and is of a hard consistence and a dark reddish colour. Soils are found by analysis to contain their earthly ingredients in very different proportions. According to M. Gilbert, fertile mould in the vicinity of Turin, where the fall of rain amounts yearly to 40 inches, affords for each 100 parts, from 77 to 79 of biles, from 8 to 14 of argill, and from 5 to 12 of lime; besides about one-half of carbonic matter, and nearly an equal weight of gas, partly carbonic and partly hydrocarbonic. The same experimenter represents the composition of barren soils in similar situations to be from 42 to 88 per cent. of silicex,

(A) It was at this place, in the year 1772, that Mr Eginton invented an expeditious method of copying pictures in oil; but we do not know how far this method has succeeded. SOL

Soil, from 20 to 30 of argill, and from 4 to 20 of lime. The celebrated Bergman found rich soils in the valleys of Sweden, where the annual quantity of rain is 24 inches, to contain, for each 100 parts, 56 of siliceous sand, 14 of argill, and 30 of lime. In the climate of Paris, where the average fall of rain is 20 inches, fertile mixtures, according to M. Tillet, vary from 46 to 52 per cent. of flex, and from 11 to 17 of argill, with 37 of lime. Hence it appears that in dry countries rich earths are of a clofer texture, and contain more of the calcareous ingredient, with less of the siliceous. Mr Arthur Young has discovered, that the value of fertile lands is nearly proportioned to the quantities of gas which equal weights of their soil afford by distillation. See AGRICULTURE Index.