392 Scientific Intelligence. 
ssume a strange form with such treatment. It may be desira- 
ie, especially in pure Kinematics, to have a term to express that 
change of motion whieh measures force. But if so, is it not a 
fair demand that some new word be taken or coined for the pur- 
pose? ‘The word force has fees already used in too many differ- 
nses, 
This book i is pe a ENN and it is really elementary, even 
though in some par wing to its terseness, it is not very raped 
reading. It j is ea. the most suggestive book we know of 
the subject. H. A. N, 
18. Sound: a series of simple, entertaining and inexpensive 
— in the Phenomena pit Sound, for the use of students 
of every age; by AtFrep M. May r, Profess or of Physics in the 
satel Institute of ernest vane a "179 pp-,12mo. New Yor 
1878. (D. Appleton & Co.)—This is number two of the “ Experi- 
mental Science Series for Beginners,” of which the first volume, 
0 
re 
ingenious student can construct for himself. To present the ele- 
ments of an abstruse subject in such a way as to make the exposi- 
tion easily Pong nepaaiee by a mind not specially trained in it, 
and at the e correct and satisfactory from a scientific 
point of view, is one He the most difficult undertakings i in the work 
of an instructor. Add to sao the oer a bringing the expert 
yle @ ex riments, ate of which are novel, unite extreme 
simplicity with elegance of conception and scientific precision, and 
cannot fail to interest and stimulate the minds of the students me 
whose hands the volume may fall. The illustrations, which a 
numerous, are excellently done, and give the book a pee atric 
we Pas arin 
A Contribution to the History of Spectrum Ana nays ; by 
