5G 
PRACTICAL LESSONS. 
attempt to give tlie most important practical conclusions sug¬ 
gested by the history of man’s efforts to replenish the earth 
and subdue it; and I shall aim to support those conclusions by 
such facts and illustrations only, as address themselves to the 
understanding of every intelligent reader, and as are to be 
found recorded in works capable of profitable perusal, or at 
least consultation, by persons who have not enjoyed a special 
scientific training. 
