3888 —s- «EW. -Ailgard—Silt Analysis of Soils and Clays. 
high expectations entertained in the early days of agricultural 
chemistry. 
The important bearing of the phenomena of “ molecular coa- 
lescence” upon the formation of natural sediments, is too obvi- 
ous to require discussion. It explains at once why we s 
rarely find a deposit composed of particles of uniform hydran- 
lic value, however favorable to such a result may have been, 
apparently, the circumstances attending its formation. And it 
warns us to be careful in our estimate of the nature and velocity 
of depositing currents, as deduced from the character of the 
sediments. 
+ 
of water exerts 4 
strong influence on the coalescence of particles. It is onan 
favors the — 
jon of clay- 
nd common 
salt; the action of the latter being exemplified on ne 
of sea watel- 
a 
* This action of salt in clearing water has lately, it seems, been eg er 
new discov r. D. on, in a communication to the Bri been 4 
Society. But the clearing of muddy water by salt, as well as by alum,» tedly Te 
popular recipe for ages; and the action at the mouths of rivers 18 poin' oo 
ferred to by Mr. Sidell, in Rep. Phys. and Hydr. of Miss. River, App. 4 P 
> 
