FF, Professor at the Pasteur Institute. Translation and
introduction by P. CHAMBERS MITCHELL, M.A., D.Sc. Oxon. Illustrated.
8o. Net, $1.50.

"A book to be set side by side with Huxley's Essays, whose spirit it
carries a step further on the long road towards its goal"--_Mail and
Express._

+16.--The Hygiene of Nerves and Mind in Health and Disease.+ By
AUGUST FOREL, M.D., formerly Professor of Psychiatry in the
University of Zurich. Authorized Translation. 8o. Net, $2.00.
(By mail, $2.20.)

A comprehensive and concise summary of the results of science in its
chosen field. Its authorship is a guarantee that the statements made
are authoritative as far as the statement of an individual can be so
regarded.

+17.--The Prolongation of Life.+ Optimistic Essays. By ELIE
METCHNIKOFF, Sub-Director of the Pasteur Institute. Author of
"The Nature of Man." etc. 8o., Illustrated Net, $2.50.
(By mail, $2.70.) Popular Edition. With an introduction by
Prof. CHARLES S. MINOT. Net, $1.75.

In his new work Professor Metchnikoff expounds at greater length, in
the light of additional knowledge gained in the last few years, his
main thesis that human life is not only unnaturally short but
unnaturally burdened with physical and mental disabilities. He
analyzes the causes of these disharmonies and explains his reasons for
hoping that they may be counteracted by a rational hygiene.

+18.--The Solar System.+ A Study of Recent Observations. By Prof.
CHARLES LANE POOR, Professor of Astronomy in Columbia
University. 8o. Illustrated. Net, $2.00.

The subject is presented in untechnical language and without the use
of mathematics. Professor Poor shows by what steps the precise
knowledge of to day has been reached and explains the marvellous
results of modern methods and modern observations.

+19.--Climate--Considered Especially in Relation to Man.+ By ROBERT
DECOURCY WARD, Assistant Professor of Climatology in Harvard
University. 8o. Illustrated. Net, $2.00.

This volume is intended for persons who have not had special training
in the technicalities of climatology. Climate covers a wholly
different field from that included in the meteorological text-books It
handles broad questions of climate in a way which has not been
attempted in a single volume The needs of the teacher and student have