158 PREHISTORIC EUROPE. 



According to analyses by Phillips, Daubeny, and Payen, which 

 are given by Murchison and his eminent associates Verneuil 

 and Keyserling, 1 the black-earth is composed of siliceous sand 

 (about 70 per cent), alumina, and other mineral ingredients (23 

 per cent) and organic matter (about 7 per cent), the latter con- 

 taining nearly 2 - 5 per cent of nitrogen. A nearly similar result 

 was obtained by Hermann from three analyses, the amount of 

 organic substances being 1042 per cent. 2 Professor Gcebel some 

 years before had analysed two specimens of black-earth from 

 the neighbourhood of Saratov. 3 One of these yielded 22 per 

 cent of combustible and vegetable ingredients, and the other 23 

 per cent, the former yielding 6*25 per cent, and the latter 14*5 

 per cent of humic acid. The other ingredients consisted chiefly 

 of silica and alumina, etc., but while one specimen contained 

 only 4*50 per cent of carbonate of lime, the other showed not 

 less than 30*12 per cent. Murchison and his colleagues state 

 that the black-earth is wholly unfossiliferous, not a trace of any 

 organism, either plant or animal, having been detected by them. 

 Gcebel, however, states that in subjecting one of his specimens to 

 a mechanical separation he found, in one hundred parts, 9*7 per 

 cent of stony ingredients with "coarse organic remains," and 90'3 

 per cent of fine sifted earth. The other specimen contained 

 neither stony ingredients nor "coarse organic remains." Of 

 the 9*7 per cent of coarse-grained matter, 4*19 was made up of 

 vegetable debris, and 5*51 of clay. Unfortunately, Goebel does 

 not tell us from what depth the specimens were taken, but it is 

 probable that they were obtained at or close to the surface : he 

 describes them indeed as being " Ackerkrume " (mould). 



According to Murchison, etc., the black-earth " occupies the 

 centre of a trough, large as an European empire, having the 

 detritus of the crystalline and older rocks for its northern, and 

 the low granite Steppes and Caspian deposits for its southern, 



1 Geology of Russia in Europe and the Ural Mountains, vol. i. p. 559. 



2 Cited by Bischoff, Elements of Chemical and Physical Geology (English 

 edition, 1854), vol. i. p. 135. The reference there given is Journ. fur pract. 

 Chemie, Bd. xii. p. 290. 



3 Reise in die Steppen des sudlichen Russlands, 1838, Bd. i., p. 297. 



