Chemistry and Physics. 151 
_ lamp for a year while to rie Hats the same luminous is 
_ good argand burner costs 29 s . per year. This shows that aoa 
ing by incandescence is decidedly cheaper than lighting by gas. 
_ On the other hand, gas companies pay large dividends and ¢ 
sell their gas at much cheaper rates than at present. Arc light- 
ing is far cheaper than lighting by incandescence, at trical 
Review, vol, xi, Noy. 25, 1882, pp. 408-411. 
. Die magneto-elektrischen und dynamo-elektrischen Nak 
und die sogenannten secunddr-Batterien, mit besonderer 
Ricksicht auf ihre Construction bad ay von GusTAV GLASER- 
DsCrew. 263 pp. 12mo. Vienna, 1882 (A. Hartleben’s Verlag). 
This volume is the first of a Ae osed series of ten which are 
intended to form an seeeuied library. The titles of these 
volumes, as given in the prospectus, include all the important 
and soon. The interest felt in all these ‘subjects s at the present 
time is so deep and wide spr al that a series such as this, if well 
_ ¢arried through, cannot but be bi ighly useful. Volume I of this 
_ Series now published, dacgines the various forms of magneto- and 
dynamo-electrical machines, dividing them however into two 
on instruments for measurement is - given in the eae emis he 
descriptions in the book are clearly given, the illustrations are 
_ humerous and good; it presents in conven ee form information 
— whi pameny persons are desirous of obta 
Grorex Lunar, Ph.D., vO, ae ondon, 1882. 
(John Van Voorst). —The same , qualities o pee thorough- 
and logical system, which Dapamabhed the author’s admir- 
able “Treatise on e Acid ali,” are me nd in the 
‘present work. It is not very long since coal tar was a waste 
