446 Bibliography. 
_ Among the less extensive additions to the work, we may specify the 
method of multiplication and division by detached co-efficients,—the 
calculus of imaginary quantities, taken from the notes into the text,— 
the general properties of quadratic equations—and the value of the 
symbol 0 
ome changes have been made in the arrangement. Division by 
polynomial divisors, which was before reserved to the latter part of the 
work, is now brought under the general subject of Division near the 
beginning. The methods for elimination in equations of two or more 
unknown quantities are brought in after Simple Equations, and prob- 
lems involving two or more unknown quantities are inserted under 
Quadratic Equations. . 
There is only one important retrenchment to be noticed. The sec- 
tion on the Equation of Curves has been omitted, as the subject is now 
studied in most of our Colleges in the extended treatises of Analytical 
Geometry. 
The matter added to the work is thus much more considerable than 
that which has been withdrawn from it; and the number of pages has 
risen from 330 to 4 The work, however, in this augmented form, 
is not more extended than the majority of text-books on the same sub- 
ject; nor more extended than the present condition of collegiate in- 
struction in this department appears to render necessary. If any insti- 
tution should find more in the book than its own wants require, it woul 
be easy to omit the more advanced sections; the other portions of the 
work have still the same elementary character as before. 
The essential features of this Algebra and its characteristic excel- 
lences are perfectly retained under all the alterations which have been 
described. Those who are already familiar with rk, or with 
Stanley has wrought out the portions which he has contributed, in per- 
fect consistency with the spirit and method of the original work. There 
is no appearance of compilation—of botching heterogeneous and ill- 
assorted elements; the unity of the work is maintained from beginning 
to end. Everywhere we find that admirable method, which has been 
justly regarded as the highest excellence of this Algebra. It still pre- 
sents, in all its parts, the same faithful elaboration, the same conscien- 
forgetfulness. Every part is equally exact and finished very r 
we trace the hand of one, who y thinking through his sub- 
