196 Bibliography. 
Geine, in its agricultural sense, is a generic term. It includes all the. 
decomposed organic matter of soils.” p. 62. In a chemical senseyhe 
maintains that “the great mass of organic matter of soil is a well de= 
fined chemical compound termed geine, consisting of carbon, — 
gen, and oxygen.” 0. 
Agricultural geine, this we understand to be the equivalent of the 
humus and mould of other chemists, and to embrace the extract of 
mould, the humic acid, humin, crenic and apocrenic acids, and what- 
ever other compound has resulted from the decomposition of the or- 
ganic matter of soils. aa See may be all regarded as the 
same thing; and the farmer may be assured, that ‘differ as opinions 
may about its ultimate Hianient constitution and the. mode of action of 
geine, whether by being taken up as a solution of geine or geates, or 
only as a source of carbonic acid, the great practical lesson of all ag- 
ricultural experience, teaches that geine is essential to the growth and 
perfection of the seed; that without geine crops are not raised. Geine 
is as essential to plants as is food to animals.” p. 61. Some of the 
ablest chemists, as Liebig and Graham, do not admit the distinct exist 
ence of crenic and apocrenic acids, enumerated above as compout 
found in soils: others regard extract of mould and. humin as 
forms of humic acid. But such questions are of little practical agti- 
cultural importance, and may be safely left to the chemists to settle. 
- Dana has an opinion on these points, and his chemical geine, as we 
have seen, is ‘a well defined compound,” embracing the*humic acid, 
the humin and extract of mould of Berzelius, and the sacchulmic acid 
and sacchulmin of Liebig. Berzelius, it is well known, originally gave 
the name geine to this compound, in the French edition of his 
published in 1832; and the same name is retained in Esslinger’s French 
translation of his Traite de Chimie, published in 1840, which lies be- 
fore us. But very recently, it would seem, he has substituted humic 
acid for geine ; a mere change of name, but not of opinions respect 
ing the nature of the compound. Indeed, the distinct and definite na- 
ture of this substance seems to be admitted by as high chemical au- 
thority as almost any organic pase. gs — wtdiougs the name 
is not yet settled. 
‘The ninth principle of agricultural acineemeene that “ ‘carbonit 
cid and the i t sensi the e en and metallic 
