1 APRIL 1876, Page 23

Magnetism and Electricity. By Frederick Guthrie. (William Collins and Co.)—An

admirably written treatise, wherein all may be found which the general student requires. No less interesting will it be to those who would know the elementary principles of the science without going into the mathematical details, which Ohm's law and Wheatstone's bridge require. Mr. Guthrie can write concisely and intelligibly, with the happy mean between the two, so often disregarded by ordinary science-writers,—never sacrificing clearness for conciseness, nor insisting

on his subject at the expense of it. The chapter on galvanic batteries is especially commendable for its fullness of treatment, every special kind being commented on, and the scientific exposition of their working. Many of the experiments described are new to us, and easy of per- formance by all students, nor do they require very costly apparatus.

The author has rendered good service, too, in his appendices, where be has given the best plans and methods of procedure for making the various small instruments required.