298 
POPULAR SCIENCE REVIEW. 
not diminish, on going more deeply into the revised edition. All the early 
chapters seem to he very little altered from what was presumably up to date 
in 1866, but which is slightly antiquated now. To the end of the fourteenth 
chapter on Diamagnetism, there has been so little change that page 291 of 
the new edition corresponds with page 283 of the original work. The whole 
of this chapter, with the exception of the pagination, is evidently printed 
from the old plates, no notice being taken of the rotation of the plane of 
polarization from the polished pole of an electro-magnet, nor of that recently 
established to be experimentally determinable in air and gases. The fifteenth, 
sixteenth, seventeenth, and eighteenth chapters appear to have received 
addition amounting to only 68 pages in 485. Short chapters have been in- 
troduced on Duplex and Quadruplex Telegraphy, the Telephone and 
Microphone, and the Electric Light, which raise the size of the new volume 
92 pages in all over its elder brother of 1866. The result is patchy 
and unsatisfactory ; partly because the new and the old cohere badly ; but 
more because the totally changed point of view in which the whole subject 
is now regarded, and which is acknowledged in the preface, fails to be 
realized in the body of the work. It would be ungracious to point out 
specific errors, of which there are many. One instance, however, which 
occurred to the writer may be noted. He turned immediately to the article 
u Condenser,” for fresh information on the great development which this 
apparatus has of late years received, hoping to obtain practical hints for the 
use of mica, paraffin, and other dielectrics. There is not a syllable on the 
subject, beyond what was in the original edition. — W. H. Stone. 
ORGANIC CHEMISTRY.* 
T HE reader will be disappointed if he expects to find in this little volume 
a good general outline of Organic Chemistry. The contents remind 
one of a student’s note-book in the way statements are crowded together, 
unaccompanied by sufficient explanations, and not unfrequently damaged by 
inaccuracies. Eor instance, ethyl diamine stands for ethylene diamine 
(p. 16) ; trimetho-dichloride for trimethyl-arsine dichloride (p. 25) ; 
ethylene dichloride for dichloride. 
We are told that “ methyl alcohol is an inflammable colourless liquid, 
having an odour somewhat like ordinary alcohol, and a burning taste.” 11 It 
is generally used as a substitute for ordinary alcohol on account of its cheap- 
ness, and these two are mixed and sold as methylated spirit ” (p. 47). 
Pyrogallic acid is said to have the composition C 5 H 5 0 (CO.HO) instead 
f OH 
Of Cgllg 
- OH — an important difference (p. 127). 
.OH 
About 170 pages are devoted to this part of the book ; the remaining 
portion being answers to questions from the Examination Papers of the 
Science and Art Department. 
* “ A Manual of Organic Chemistry.” By Hugh Clements. Sm. 8vo. 
London : Blackie & Son, 1879. 
