Mr. Babington, in his Manual of Botany, enu- 
merates twenty-one species of Trefoil as indigenous 
to Great Britain ; half of these may, however, be 
regarded as botanical curiosities rather than com- 
mon or forage plants. In the science of agricul- 
ture (agriculture well deserves the title of science) 
several Trefoils are esteemed as valuable ; particu- 
larly Trifolium pratense, or Red Clover, and Tri- 
folium repens, or White Clover. The former of 
these is exceedingly valuable, not alone on account 
of its abundant ju'oduce, but also on account of its 
restoration of land to a state fitted again for the 
cereal grains, as wheat, &c. But here, we are sorry 
to mention, that the science of agriculture is yet 
exceedingly imperfect. Practice has shown disap- 
pointing results, but science has not yet (as we 
expect it will) explained the remedy. Clover can- 
not be frequently cultivated on the same laud. The 
same may be said of other crops, but their results 
are less striking. The land, as the farmer says, 
tires of it; and the fact is, becomes incapable of 
producing it. Several crops of this Clover, even at 
intervals of two or three years, will so emjity the 
soil of the particular sort of food it requires, that 
succeeding crops upon the same land will be fam- 
ished. The usual manures prove unavailing. The 
earth's storehouse must again be gradually replen- 
ished by absoiqjtion from rains and the atmosphere. 
Here is a fact — shown by practice, and hitherto 
irreparable. Science, ere long, may be expected 
to su2>iily the remedy, and assist the farmer in re- 
plenishing his soil, with the same certainty as by 
the growth of any crop it is imjioverished. 
