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is testing the powers of nature by the crucible and the bal- 
ance and all those reagents which bring into play the affini- 
ties of matter; the latter is acting upon the intellectual 
powers of the community, and putting in motion far and 
wide over the land those mental agencies which result in 
wider general knowledge, higher culture, sounder practical 
judgments, and more productive industry. It is sometimes 
difficult to say which of these two classes of laborers con- 
fers the largest benefits upon the world. Nor, indeed, need 
we attempt to decide upon their respective merits. It is 
sufficient that they are both necessary to the highest ends of 
science. It was the fortune of our friend to act, for the 
most part, as the diffuser of knowledge. And by what cri- 
terion shall we estimate the obligations which we owe to him 
in this respect. 
It was said of Dr. Black, by a very competent judge * of 
his scientific merit, that “ his influence on science was chiefly 
exerted through the medium of his pupils and of his inter- 
course with general society.” With equal truth may this be 
said of Professor Silliman, and especially when we consider 
the vast extent of his field of instruction. Among the pupils 
of half a century how many have caught the enthusiasm of 
the master and given their energies to science, and placed 
their names high on the list of its honored cultivators! How 
many hundreds and thousands of those who, in different cities, 
have listened to his eloquent lectures, have learned to ap- 
preciate science, and gather refined pleasure from its culture, 
and give to it their hearty patronage! How regularly and 
how widely has his Journal carried to the reading public 
intelligence of the latest discoveries, and the best practi 
ae ee of science ! 
= ing all this, who shall say that his efficient infla- 
: a | # Prof J.D. Forbes, Encye. Brit., 6th Dissertation, p. 927- 
