INTRODUCTION. 39 
indeed, not an American, but for a quarter of a century 
a resident in the United States. 
Mr. Sat, a native of Philadelphia, the son of a phy- 
sician, but himself for some years a merchant, seems to 
have been the earliest scientific naturalist, of the modern 
school, which the country has produced. He possessed 
a well-balanced mind, powers of accurate observation and 
discriminating perception, and a facility of expressing his 
thoughts in a brief and condensed style. He was trained 
to habits of industry and perseverance ; his temper was 
mild and equable ; and his maimers were so modest and 
retiring as to excite remark. His acquirements as a 
naturalist were due to his private studies alone ; for at 
the period when his character was forming, there were 
few or none engaged in kindred pursuits, — no associa- 
tions of naturalists, in the bosom of which he could find 
sympathy and support, and few libraries to which he 
could resort for knowledge and assistance. The great 
zoological names which have illustrated the nineteenth 
century had not then appeared, or, in consequence of 
the disturbed relations of this government with European 
powers, their works were mostly unknown here. But, 
notwithstanding the deficiency of his means and oppor- 
tunities, he possessed himself of the learning and accom- 
plishments of the day, in a much greater degree than 
could have been expected in his position ; and was ready 
and prepared, at the commencement pf the new career 
of science on which his country entered soon after the 
termination of the European wars, to make that advance 
