On Rnpe-dnxt. 
187 
oxyp^en and liytlrofjen, to form ammonia with the nitrogen in the 
manure, and to dissolve the inorganic matters it requires — that 
moisture without which every farmer is aware no crop can be 
productive. 
This is no delusive advantage. In the first place, it has been 
proved by Sir Humphry Davy, Professor Schublcr, and Cuth- 
bert Johnson, Esq. (and it may be proved by any one), that or- 
ganic manures, such as rape-dust, possess the power of absorbing 
from TWICE to ten times as much atmospheric moisture as the 
finest soils. It is also equally well proved that the more a soil is 
pulverized, and the finer the state of division in which its parts 
are, the greater is its absorbent power* Now, the effect of the 
decomposition of any matter in a soil is an increased pulverization 
of the earths in contact with it.f Hence we are justified in con- 
* " The power of the soil to absorb water by cohesive attraction 
depends in a great measure on the state of division of its parts : the 
more divided they are, the greater is their absorbent power. The differ- 
ent constituent parts of soils likewise appear to act, even by cohesive 
attraction, with different degrees of energy : thus vegetable substances 
seem to be more absorbent than animal substances, animal substances 
more so than compounds of alumina and silica, and compounds of 
alumina and silica more so than carbonates of lime and magnesia : these 
differences may, however, depend upon the differences in their state of 
division, and upon the surface exposed. . . 1 have compared the ab- 
sorbent power of many soils with respect to atmospheric moisture, and 
I have always found it greatest in the most fertile soils." — (Sir Hum- 
phry Davy, Agr. Chem., page In these trials, " 1000 parts of a 
celebrated soil from Ormeston in East Lothian, which contained more 
than half its weight of finely-divided matter, of which 11 parts were 
carbonate of lime and 9 parts vegetable matter, when dried 212°, gained 
in an hour, by exposure to air (saturated with moisture at a temperature 
of 62^), 18 parts; 1000 grains of a coarse sand, worth 15?. per acre, 
gained 11 grains; 1000 grains of the soil from Bagshot Heath 
gained only 3 grains." — (Sn H. Davy, Agr. Chem., p. 176.) Accord- 
ing to Cuthbert Johnson (vide ' On Fertilizers,' p. 41), 1000 parts of 
horse-dung, dried in a temperature of 100^, by exposure three hours to 
air, saturated with moisture at a temperature of 62^, gained 145 ; and 
1000 parts of rich alluvial soil only 14. In the experiments of Pro- 
fessor Schubler (w'f/e 'Journal of Royal Agr. Soc.,' vol. i., p. 210)— 
1000 grs. of Immus (vegetable and animal mould) absorbed 80 grs. in 12 hours. 
1000 grs. of garden soil 35 grs. in do. 
1000 grs. of arable soil . . . . , . 16 grs. in do. 
t TuU was aware of this, and explained the good effects arising from 
manure by it. Thus, says he (' New Husbandry,' p. 166), Almost the 
only use of all manure is the same as of tillage, viz. the pulverization 
it makes by fermentation, as tillage doth by attiition or contusion." — 
Tlie Author. 
