
Dec. 22, 1870] 
NATURE 
145 

This chapter is concluded by twenty-three problems | 
and questions referring to weights and measures and 
specific gravities. Throughout the book temperatures 
are expressed in centigrade degrees, and the metrical 
system is employed. Next, we have chapters on funda- 
mental chemical relations and molecules, and the re- 
lations of the latterto heat. Chapter 1V. treats of Atoms 
and Chap. V. of Chemical Notation. Under this head we 
observe several definitions and modes of formulation 
which are not usval in this country. Thus chemical re- 
actions are divided into three classes, analytical, syn- 
thetical, and metathetical, the latter including double 
decomposition, displacement, and re-arrangement. The 
symbols are usually printed in italics, but solid bodies 
are formulated in “ full-faced” type, and gases in skeleton 
type ; and when reactions take place in aqueous solution 
this is expressed in the equation by including the dis- 
solved bodies in brackets with the symbol 4g: thus, 
(Ca Cl,+ H,O + Ag) shows that the calcic chloride is in 
solution, and that the quantity of water represented by 
77,0 isa result of reaction, In the chapter on Stochio- 
metry (though Stoichiometry seems more correct) are a 
number of modes of calculation of formule, and of the 
relations between weight and volume ; and under Chemi- 
cal Equivalency is a kind of constitutional formulae which 
somewhat differs from those in general use. Professor 
Cooke follows the principle laid down by Dr. Frankland 
that chemical formulze should represent, as far as possible, 
the relations existing between the atoms of a compound ; 
but he has thought it advisable to place the grouping 
element or radical at the end of the formula instead of 
the beginning ; this, we think, is to be regretted, as it 
adds another to our already numerous modes of formu- 
lation. Short strokes are placed at the side of the 
grouping element or radical to indicate the direction of 
the attractions ; thus the formula for Ethylacetamide is 
H, C, H.,C, H, O = N, showing that the hydrogen, ethyl, 
acetyl, are united directly to the nitrogen, the commas 
indicating that they are not united among themselves : 
Diethylurea ,, (C, .),, = N, = € O is another instance. 
When these short strokes become numerous they are 
rather confusing, asin Turquoise, O, =[AZ,], =|0;, =(P O.). 
Graphic formule of Kekulé’s and Crum Brown’s form are 
explained, and students are advised to make frequent use 
of them, but not to abuse them. The nomenclature em- 
ployed is that which is frequently used in England, and 
which Mr. Cooke designates as that of the London Chemi- 
cal Society, though we think that some of the Fellows dis- 
approve of such terms as zincic sulphate, &c. The physical 
relation of chemical bodies, as crystallography, electro- 
lysis, spectrum analysis, and heat of chemical com- 
bination, are treated at some length. The elements are 
divided into sections according to their atomicity, the 
perissads being taken first and afterwards the artiads. 
This arrangement places oxygen beyond the middle of 
the book, instead of near the commencement as usual. | 
The occurrence, mode of preparation, and properties, of | 
the elements, and of their more important compounds, 
are very concisely given. Carbon is described as oc- 
curring in three forms, diamond, graphite, and coa/. This 
last term seems an unfortunate one for amorphous carbon, 
as some coal contains as little as 73 per cent. of the 
| the cultivation of the individual flower. 

element. Under the compounds of carbon is a section 
on Organic Chemistry which extends over only sixty pages 
Although it contains a vast amount of information, and 
organic compounds are mentioned throughout the book, 
yet it seems rather a meagre account of the enormous 
developments of this branch of science. At the end of 
the book are tables of French measures and weights, of 
elements, of the specific gravities of gases and vapours, 
and of logarithms and antilogarithms. We wish this 
book success, as it indicates great vitality in Transatlantic 
chemistry. 


OUR BOOK SHELF 
Elementary Treatise on Natural Philosophy. By Pro- 
fessor A. Privat Deschanel, of Paris. Translated and 
edited, with extensive additions, by Prof. Everett, Del 
of Belfast. In 4 parts. Part 1-—Mechanics, Hydro- 
statics, and Pneumatics. (Loncon : Blackie and Sons.) 
THIs translation of Prof. Deschanel’s “Traité de Phy- 
sique” will, we believe, be found extremely useful. An 
elcmentary treatise of moderate size on Physics has been 
long wanted in our schools. _ Atkinson’s translation of 
Ganot, or Brook’s Natural Philosophy, is too expensive 
for general use, and of smaller books, none, so far as we 
know, are good. The issue of Dr. Everett’s translation 
in parts at the moderate price of 45. 6d., will enable it to 
be largely employed. The engravings with which the 
work is illustrated are especialiy good, a point in which 
most of our English scientific works are lamentably defi- 
cient. The present part contains Mechanics, Hydrosta- 
tics, and Pneumatics. The clearness of Deschanel’s 
explanations is admirably preserved in the translation, 
while the value of the treatise is considerably enhanced 
by some important additions. Thus, to Deschanel’s 
description of the pendulum is added a short account of 
the condition of isochronous vibration, moment of inertia, 
momentum, and kinetic and potential energy. In the sec- 
tionon Pneumatics, Deschanel’sextremely good description 
of the air-pumps of Hawksbee, Bianchi, Kravogl, Geissler, 
and Deleuil, is supplemented by an account of Sprengel’s 
mercurial pump. It is possible to point out defects, but 
they are few. The conception of “mass” is alwaysa 
difficult one for a beginner. Deschanel gives a very clear 
explanation, which is not reproduced, the term being em- 
ployed without explanation. Nor do we understand why, 
instead of Deschanel’s statement that the co-efficient of 
absorption of ammonia in water at O°C, is 1050 (exactly 
it is 1150), it is said to be only 600, But these are 
minor defects, and we repeat that we believe the book will 
be found to supply a real need. W. M. W. 
The Wild Garden ; or, Our Groves and Shrubberies made 
beautijul by the Naiuralisation of Hurdy Exotic Plants. 
By W. Robinson. (London; Murray.) 
THISs little volume forms a fitting sequel to Mr. Robinson’s 
admirable book, “ Alpine Flowers for English Gardens,” 
which we noticed some time back.* It does not contain 
nearly such a large amount of novel information, but will 
nevertheless be of great value to all lovers of their gardens. 
The book is a protest against the practice which com- 
menced some twenty years since, and reached its height 
a year or two back, of throwing the whole cnergies of the 
gardener into producing large masses of colour by the use 
of what are termed “bedding plants,” to the exclusion or 
This somewhat 
barbaric taste has resulted in the gradual dise ppearance 
from our gardens of many flowers which had been “ house- 
hold words” since the time of Shakespeare, to the great 
detriment, as Mr. Robinson considers, of gardening as 
a real art, and to the enormous increase of its expense. 
* Naturg, vol. i, p. 603. 
