opinions of the Press on the ''^ International Scientijic Series." 



XVII. 



Money and the Mechanism of Ex- 

 change. 



By W. STANLEY JEVONS, M. A., F. R. S., 



Professor of Logic and Political Economy in the Owens College, Manchester. 



I vol., i2mo. Cloth. Price, $1.75. 



" He offers us what a clear-sighted, cool-headed, scientific student has to say on the 

 nature, properties, and natural laws of money, without regard to local interests or na- 

 tional bias. His work is popularly written, and every page is replete with solid instruc- 

 tion of a kind that is just now lamentably needed by multitudes of our people who are 

 victimized by the grossest fallacies." — Popular Science Monthly. 



" If Professor J evons's book is read as extensively as it deserves to be, we shall 

 have sounder views on the use and abuse of money, and more correct ideas on what a 

 circulating medium really means." — Boston Saturday Evening Gazette. 



" Professor Jevons writes m a sprightly but colorless style, without trace of either 

 prejudice or mannerism, and shows no commitment to any theory. The time is not 

 very far distant, we hope, when legislators will cease attempting to legislate upon 

 money before they know what money is, and, as a possible help toward such a change. 

 Professor Jevons deserves the credit of having made a useful contribution to a depart- 

 ment of study long too much neglected, but of late years, we are gratified to say, be- 

 coming less so." — T/ie Financier, New York. 



XVIII. 



The Nature of Light, 



WITH A GENERAL ACCOUNT OF PHYSICAL OPTICS. ' 

 By Dr. EUGENE LOMMEL 

 (University of Erlangen).' 

 I vol., i2mo. Cloth. . . . Price, $2.00. 



" In the present treatise, Professor Lommel has given an admirable outline of the 

 nature of light and the laws of optics. 



" Unlike most other writers on this subject, the author has, we think, wisely post- 

 poned all reference to theories of the nature of light, until the laws of reflection, re- 

 fraction, and absorption, have been clearly set before the reader. Then, in the fifteenth 

 chapter. Professor Lommel discusses Fresnel's famous interference experiment, and 

 leads the reader to see that the undulatory theory is the only conclusion that can be 

 satisfactorily arrived at. A clear exposition is now given of Huyghen's theory, after 

 which follow several chapters on the diffraction and polarization of light-bearing waves. 



" The reader is thus led onward much in the same way as the science itself has un- 

 folded, and this, we think, is the surest and best way of teaching natural knowledge. 



"We have said enough to show that Professor Lommel's treatise is a useful contii- 

 bution to the ' International Series' — a book that can thoroughly be Understood and 

 enjoyed by any intelligent reader who may not have had any special scientific train- 

 ing." — Nature. 



" In a style singularly lucid, considering the abstruse nature of the subject treated. 

 Dr. Lommel unfolds the learning of the scientists on the nature and phenomena of 

 light." — Philadelphia Inquirer. 



" As a popular introduction to physical optics,' it would be difEcult to find a more 

 satisfactory work than the one by Dr. Lommel, which has just appeared in the excel- 

 lent ' International Scientific Series.' " — The English Mechanic. 



D. APPLETON & CO., Publishers, 549 & 551 Broadway, N. Y. 



