tions to his theories win for him a
close attention and sustained effort, on the part of the reader,
to comprehend, follow, grasp, and appropriate his principles. This
book, independently of its bearing upon sociology, is valuable as
lucidly showing what those essential characteristics are which
entitle any arrangement and connection of facts and deductions to
be called a _science_."--_Episcopalian._

"This work compels admiration by the evidence which it gives of
immense research, study, and observation, and is, withal, written
in a popular and very pleasing style. It is a fascinating work, as
well as one of deep practical thought."--_Bost. Post._

"Herbert Spencer is unquestionably the foremost living thinker in
the psychological and sociological fields, and this volume is an
important contribution to the science of which it treats.... It
will prove more popular than any of its author's other creations,
for it is more plainly addressed to the people and has a more
practical and less speculative cast. It will require thought, but
it is well worth thinking about."--_Albany Evening Journal_.

VI.

The New Chemistry.

By JOSIAH P. COOKE, Jr.,

Erving Professor of Chemistry and Mineralogy in Harvard University.

1 vol., 12mo. Cloth Price, $2.00.

"The book of Prof. Cooke is a model of the modern popular science
work. It has just the due proportion of fact, philosophy, and true
romance, to make it a fascinating companion, either for the voyage
or the study."--_Daily Graphic._

"This admirable monograph, by the distinguished Erving Professor
of Chemistry in Harvard University, is the first American
contribution to 'The International Scientific Series,' and a more
attractive piece of work in the way of popular exposition upon a
difficult subject has not appeared in a long time. It not only
well sustains the character of the volumes with which it is
associated, but its reproduction in European countries will be an
honor to American science."--_New York Tribune._

"All the chemists in the country will enjoy its perusal, and many
will seize upon it as a thing longed for. For, to those advanced
students who have kept well abreast of the chemical tide, it
offers a calm philosophy. To those others, youngest of the class,
who have emerged from the schools since new methods have
prevailed, it presents a generalization