Reviews. 
Quid sit pulchrura, quid turpe, quid utile, quid non.—Hon. 
Chemistry for Students. By Alexander W. Williamson, 
F.R.S., Professor of Chemistry in University College, 
London, &c. New edition. Oxford, at the Clarendon 
Press. 1868. 
This work contains a clear, concise, and systematic account 
of many of the facts and fundamental principles of chemistry, 
so arranged and so treated as to enable the diligent student 
to become possessed of such a knowledge of the science as 
will enable him to rely on it as a sound basis for more ex¬ 
tended acquirements. 
Dr. Williamson, like some other authors, has adopted a 
method of exposition which differs from that usually em¬ 
ployed by chemical writers; ‘^for I,^’ says he in his preface, 
describe and compare individual facts, so as to lead the 
mind of the reader towards general principles, instead of 
stating the general principles first, and then proceeding to 
illustrate them by details.” This mode of treating a scientific 
subject like chemistry, which owes its advancement mainly to 
the inductive mode of investigation, is the natural, rational, 
and safest method of exposition, and any work which, like 
Dr. Williamson’s, successfully carries this principle into 
practice, can confidently be commended to the notice of all 
persons desirous of becoming acquainted with the facts of 
chemistry and their applications, as well as with the kind 
of reasoning upon which the theories of chemists have been 
established. 
We might take objection to some parts of Dr. Williamson’s 
work; for example, investing hypothesis with the character of 
fact. In speaking of atoms, the existence of which are denied 
by mathematicians, and only assumed for convenience by 
chemists, he says, “ but in no case has any of them been 
broken up into smaller particles, nor built up from smaller 
ones.” Thus the reader would be led to regard atoms, not 
as what they really are, mental conceptions, but as physical 
entities whose existence is capable of experimental demon¬ 
stration, thus fail to draw the distinction between theory 
and fact, and to appreciate their relative importance, and to 
benefit by tbe assistance which such an acquisition renders 
