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RELATION TO PHYSICAL SCIENCES. 
progress of knowledge led onwards by the 
united sciences. Each pressing forward 
from dawn to daylight, shedding upon its 
fellows the shining beams as soon as they 
are received. 
Geology owes much of its interest and 
certainty to the study of organic remains ; 
if it had continued to treat of mineral 
masses alone, it would have retained a sub¬ 
ordinate place amidst the subjects of hu¬ 
man inquiry. The phenomena of aggre¬ 
gation, deposit, crystallization, cleavage, 
metamorphism, and elevation, are topics of 
severer aspect than the investigation of the 
'' medals of creation.” 
Botany appeals to her dark sister for the 
restoration of some links in the chain of 
present vegetation, apparently lost, but only 
buried. Plants which have perished from 
the earth with all their varieties, species, 
and genera, are highly instructive helps in 
the study of the existing vegetable king¬ 
dom. 
The miner finds the fragments of plants 
useful in guiding his works amidst barren 
clays and productive coal-beds. The differ- 
