the Progress of English Agriculture. 809 = 543 
A knowledge of the chemical composition of the soil upon Use of a know- 
hich it is desired to raise certain crops, and of those soil- '^dge ot' the 
mstituents which are essential to their very existence and Tl' 
-11 *i*i r ^ \ n • position 01 tiie 
crfect development, is obviously useful to the farmer, for it will soil, 
low him, for instance, in a direct and ready manner, whether 
le land is deficient in lime, and would be improved by marling 
r liming. 
At one time both farmers and chemists thought analyses 
ould solve all the difficulties which practical men meet in 
iltivating soils of low fertility, the occupier of which ex- 
riences much disappointment by his frequent failure to raise 
•munerative crops upon them. 
Further experience, however, has proved that in many cases Analyses do not 
ere numerical analytical results are not calculated to assist the f'^'ays show its 
rmer in improving his land, or to inform him of the cause capabilit'ies. 
non-success in growing certain crops — why, for instance, he 
nnot grow clover on some soils. There are many apparently 
milar soils — that is to say, soils in which analysis shows like 
lantities of the same constituents — such as potash, soda, lime, 
agnesia, phosphoric, sulphuric, and silicic acids — and in which, 
)t withstanding, the same kind of manure produces a good result 
one case and an unfavourable one in another. This plainly 
ows that the analysis of soils, as usually performed by chemists, 
)es not afford in all cases a sufficient guide to an estimate of 
eir agricultural capabilities, nor to point out the kind of 
anure which is particularly well adapted for the special crops 
tended to be grown. Even the detailed analysis of a soil 
ually gives only the proportions of its different constituents, 
d generally without reference to the states of combination in 
lich they exist in the soil ; and it is altogether silent on the 
operty possessed by all soils in a higher or lower degree, of 
ecting striking and important changes in the manures which 
3 incorporated with the land. Analyses of soils, therefore, 
must be confessed, are often disappointing in their practical 
arings. However, the obvious insufficiency of bare analytical 
ures to afford satisfactory answers to the questions which 
riculturists put to agricultural chemists have had the effect 
< stimulating further scientific inquiries into the mysteries of 
.' .Is, and these inquiries have not been without success. Just 
j proportion as our scientific knowledge of the properties of 
i Is has been increased, the practical utility of these investi- 
ftions has been enlarged. 
The discovery by the late Sir H. S. Thompson of the Absorbent 
5orbent power of soils (or the power possessed by a soil to " 
ompose and retain for the sustenance of plants the am- 
)niacal and other salts which form the most valuable con- 
