Notices respecting New Books. 147 
thods, that while he takes the beautiful apparatus of Regnault as his 
model, he avoids his method of determining volumes by ascertaining 
the pressure of a constant volume. 
The operations of gaseous analysis, more perhaps than any of the 
numerous branches of chemical research, involve the necessity for 
skill and tact in the construction and management of delicate appa- 
ratus. For some years past we have been accustomed, in perusing 
the researches of the more distinguished of his pupils, to notice how 
greatly the production of those researches was facilitated by the use 
of appliances having a character peculiar to the contrivances of 
Bunsen. They possess a neatness, a perfect adaptation to the pur- 
pose in view, which renders it as easy to distinguish the style of 
Bunsen in his apparatus, as of some artists in their pictures. The 
same remark applies with equal, if not greater force, to instruments 
owing their origin to Regnault. 
We find in the work before us a complete treatise, not merely on 
the methods of examining and analysing gases, but on the construc- 
tion of all the apparatus described, and the manipulation necessary 
therewith. 
The work commences with a description of the methods of col- 
lecting gases from geisers and springs, with certain parts of the ap- 
paratus for which we are familiar, modifications of them having been 
used in some of the researches of Bunsen’s pupils. The same remark 
applies to much of the apparatus used in the transference of gases, 
we having already become acquainted with the peculiar glass gaso- 
meter (fig. 16), described in a paper of Dr. Maxwell Simpson’s 
(worked out in Bunsen’s laboratory) on some new methods of deter- 
mining nitrogen. 
The construction and graduation of eudiometers, according to the 
author’s own method, is very fully entered into; and now that che- 
mists are pretty generally agreed on the superiority of his plan over 
any other, will be found very useful. 
One great advantage of the work is, that none of the more minute 
details are omitted on the score of their being unimportant; such, 
for example, as the best and safest mode of cleaning eudiometers, 
&e. ‘The book becomes, therefore, a truly practical guide for the 
working chemist. 
Those who have been accustomed to eudiometrical analyses, have 
all found how much time is often wasted owing to the electrical ap- 
paratus being more or less out of order, or the atmosphere of the 
laboratory being so damp as to render it difficult at a short notice 
to obtain a spark strong enough to fire the mixture. ‘This difficulty 
is entirely avoided by the contrivance described in the book, which, 
on account of its extreme usefulness, we transfer to our pages. 
“The firing of the gaseous mixture is always effected by the elec- 
tric spark. A small cylinder about 3 inches high and 1 broad serves 
as a Leyden jar. ‘This cylinder is lined inside with tinfoil; but in 
order to avoid amalgamation, the outer metallic coating consists of 
platinum-foil. Electrophori, or common electrical machines, are 
very apt to become useless by remaining in the damp and cold 
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