Analysis of Soils. 371 
inrist te search out different methods of culture, in caseg 
where the culture should be similar. Take the examples be- 
fore given, allowing each to compose sixty per cent. of the 
soil. The quartz would give silex about 55, alumine 5—the 
feldspar about 38 silex, 12 alumine, 9 potash, 1 oxyd of iron - 
—the hornblende abvut 25 silex, 8 alumine, 7 lime, 1 mag- 
nesia, 18 oxyd of iron, 1 manganese—the sapphire about 54 
alumine, 5 silex, 1 oxyd of iron—the diamond just 60 of 
the basis of charcoal. From these different results, the agri- 
culturist would infer, that each soil should require a peculiar 
in all other primitive countries. It seems to be necessary, 
therefore, that the stones, pebbles, and sand, should be sepa-~ 
rated at the commencement of the process, or immediately 
after the combined water and animal and. vegetable sub- 
stances are separated ; and that the remainder should be ana- 
lyzed by itself. 
Fortunately for agriculturists, pebbles, sand, or whatev- 
hat hard part of soils. which can 
can be entirely sepa- 
rated from the remainder in about three minutes. After pick- 
ing out the stones, i 
put the soil into an assay glass, or high tumbler, and pour in 
water and stir the mixture. The coarse pebbles immediate- 
ly fall to the bottom and form a distinet stratum, from which 
the finer soil may be removed and washed off clean. The 
ighed, and all the fine soil dried and palverssed. 
inthe usual way. We now put the pulverized oats inte 
upernatant liquid, 
a eee ak it. Then proceed with the part which 
remained in suspension in water minutes, in the 
in various 
aga aee es the same principle which causes. 
this precipitation is the most important peg —*. 
the growth of plants. It falls to the honaw oes 
not strongly attract water, as the clayey om ae sails ee 
Being made up of hard fragments, water ber 
