4 6 4 
Analyses of Boohs . 
[July 
Heat , a Mode of Motion. By John Tyndall, D.C.L., LL.D., 
F.R.S. Sixth Edition. London : Longmans and Co. 
When a scientific book — and especially one which has not earned 
popularity by appealing to unscientific or anti-scientific prejudice 
—reaches its sixth edition the ground for the reviewer is much 
narrowed. If he censure, the majority is against him ; if he 
praise, or merely expound, his readers, if men of high culture, 
call his critique an I lias post Homerum , or, if of a more vulgar 
stamp, they long to confer upon him that vindicative pinch which 
in some rural districts is still bestowed upon the bringer of stale 
The volume before us is not a reprint ; it has been modified, 
improved, and extended. Upon one remark in the Preface we 
must pause for a moment. Says the author — “ Far be it from 
me to claim for Science a position which would exclude other 
forms of culture. A distinguished friend of mine may count on 
an ally in the scientific ranks when he opposes, on behalf of 
literature, every attempt to render science the intellectual all in 
all. Ours would be a grey world if illuminated solely by the dry 
light of the understanding.” This is well said ; but as there is 
no earthly prospect of Science ever becoming the “ intellectual 
all in all,”— would not “ mental ” be the better word ?— as there 
is no possibility of “ other forms of culture ” being excluded, 
such concessions seem scarcely needful. But at least every man 
should have his free choice, and not be forcibly restrained from 
studying things without he has first spent a serious portion of 
his life upon words. 
In the Preface we find an interesting notice of a work ot 
Carnot’s, written and published as far back as 1824, in which he 
developes the relation between heat and work which has since 
been independently discovered by Mayer and Joule. 
It is somewhat remarkable that whilst the modern view of 
heat as a mode of motion was generally held by scientific men 
and philosophers in the seventeenth and the earlier part of the 
eighteenth centuries, — e.g., Locke, Boyle, Euler, &c., the op- 
posite or material theory seems to have gained ground in the 
first half of the present century, especially in France, where 
even such a man as Berthollet came forward on behalf of the 
“ received theory of caloric” — a word still used by leader-writers 
in their often indiscreet “ meddling and muddling ” in scientific 
questions. _ _ _ . . , 
A very interesting fadl is that established by Prof, rrankland, 
that, by merely condensing the air around it, the pale flame of a 
spirit-lamp may be rendered luminous, and even srnoky, “the 
oxygen being by the compression rendered too sluggish to effect 
the complete combustion of the carbon.” 
We find it mentioned that the liquefaction of chlorine was 
effeaed by Northmore as early as 1805, and it is at least probable 
