( 394 ) July, 



NOTICES OF BOOKS. 



Elementary Treatise on Natural Philosophy. By A. Privat- 

 Deschaxel. Translated and Edited, with Extensive Addi- 

 tions, by J. D. Everett, M.A., D.C.L., F.R.S.E., Professor 

 of Natural Philosophy in Queen's College, Belfast. Part IV. 

 Sound and Light. London : Blackie and Son. 1S72. 

 This is the last part of Dr. Everett's admirable handbook. The 

 arrangement, which we have previously noticed as methodical 

 in the highest degree, appears in no one of the three other 

 volumes so logical as in this. The comparison and contrast of 

 the vibrations of light and sound are calculated to afford mate- 

 rial assistance to the understanding of the phenomena presented 

 successively to the student, especially in the case of the difficult 

 problems of polarisation and interference. L'nder the head of 

 Acoustics there are considered the production and propagation 

 of sound, its numerical evaluation, modes of vibration, conso- 

 nance, dissonance, and resultant tones. Under Optics the sub- 

 divisions are propagation and reflection, refraction, lenses, 

 optical instruments, dispersion and spectra, colour, the wave 

 theory of light, and polarisation. The chapters on the wave 

 theory of light and the numerical evaluation of sound are parti- 

 cularly worthy the student's attention ; and he will find the 

 illustrations as clear, and as fine specimens of wood-engraving, 

 as in the former parts of the work. 



A Manual of Recent and Existing Commerce. From the Year 

 17S9 to 1S72. By John Yeats, LL.D., &c. London : 

 Virtue and Co. 1S72. 

 Dr. Yeats is already well known by his works on the technical 

 and natural history of commerce, the growth and vicissitudes of 

 commerce, Sec. The title of the present work is sufficiently 

 self-explanatory. The history is inclusive, and, as far as may 

 be. exhaustive; it is rendered so by. the author's terse style and 

 syllogistic method. The preface states the work to be a means 

 of preparation for the higher departments of commerce, or as 

 affording matter for reflection during intervals of repose ; that 

 it will assist an intelligent reader in arriving at sound conclusions 

 with regard to the credit of any single state, and aid him in a 

 study of the present or prospective position of our own country, 

 we fully agree. We have especially to draw attention to the 

 history and principles of banking as exemplified in the affairs of 

 the L'nited States and of our own national bank. The particulars 

 of a bank-parlour inspire an ordinary person with considerable 

 awe; but on the perusal of such a work as this the transcen- 

 dental interest speedily gives place to a deeper respect for com- 

 mercial integrity and a right appreciation of the demerit of all 



