ELECTRICITY AND MATTER. By Joseph John Thomson, d.s.c., l.l.d, ph.d., f.r.s., Fellow of Trinity College and Cavendish Professor of Experimental Physics, Cambridge University.

(Fourth printing.) Price $1.50 net.

THE INTEGRATIVE ACTION OF THE NERVOUS SYSTEM. By Charles S. Sherrington, d.sc., m.d., hon. ll.d. tor., f.r.s., Holt Professor of Physiology, University of Liverpool.

(Fifth Printing.) Price $5.00 net.

RADIOACTIVE TRANSFORMATIONS. By Ernest Rutherford, d.sc, ll.d., f.r.s., Macdonald Professor of Physics, McGill University.

Price $5.00 net.

EXPERIMENTAL AND THEORETICAL APPLICATIONS OF THERMODYNAMICS TO CHEMISTRY. By Dr. Walter Nernst, Professor and Director of the Institute of Physical Chemistry in the University of Berlin.

Price $1.50 net.

PROBLEMS OF GENETICS. By William Bateson, m.a., f.r.s., Director of the John Innes Horticultural Institution, Merton Park, Surrey, England.

(Second printing.) Price $5.00 net.