354 Olmsted’s Introduction to Natural Philosophy. 
nature or art, we may avail ourselves of principles taken from every - 
part of the science,—a circumstance which is frequently of greatim- 
gee the full and complete explanation of a natural phe 
~ On this point, a gentleman who has taught the work to a class, and 
wha is very competent to judge of its merits, has furnished us with 
the following observations. ‘* The arrangement adopted in Olmsted’s 
lotroduction to Natural Philosophy, I have found to posses peculiar 
wees: By separating the “ mathematical elements” from the 
: tical part,” and confining the student, at first, exclusively to the 
fauna his attention is not diverted from the fundamental principles 
of the science; but these he studies with the same interest as he 
does branches of the pure mathematics and understands them as 
perfectly. Those who have either taught or studied Enfield’s Phi- 
losophy, know that quite the reverse is true in regard to that system, 
in which the theoretical and practical parts are so blended that each 
the interest of the other. The pleasure derived from the 
contemplation of abstract truths depends on qualities of the mind.so 
different from those which delight to follow out their application: to 
useful and economical purposes, that the two kinds of interest can 
hardly exist together inthe mind, but, by a kind of incompatibility; 
tend to neutralize one another. Jn this-Treatise also, the funda- 
mental principles of Natural Philosophy, are impressed. upon the 
mind of the learner by a great variety of problems annexed to each 
chapter, which, in addition to the intellectual advantages, usually at- 
tendant on the solution of mathematical problems, serve to render the 
student exceedingly familiar with those principles. ‘Thus, the most 
difficult parts of the work having been first mastered, the perusal of 
what relates to the practical applications, is easy and delightful. In 
this part of the work, moreover, there is embodied an amount of uselu 
information rarely to be met with in works of this size. _ In short, both 
the plan and execution of the work are such as can hardly fail, tis 
believed, to commend it to all experienced instructors.” uae 
Part I., to which so much importance is justly ascribed, is abridged 
with numerous additions and alterations, from a Treatise on Me- 
chanics, published a few years since for the use of the students of the 
East India etaibe, by the Rev. B. Bridge, fellow of St. John’s 
College, Cam abridge. We know not where a work could have | been 
found better adapted to the purpose.. Bridge is an y Ju 
minous writer ; and his Mathematical Treatises bear the oon 
a mind well informed of its subject, and (whichis quite asi 
