238 
Analyses of Boohs. 
[April, 
advantage. There is a very considerable convenience in the use 
of solutions such that the number of degrees read off in the 
burette shows at once, without any calculation or reference to 
theories, the percentage of the body sought, — e.g. f of metallic 
tin in a sample of tin crystals. We fully admit that, to an ana- 
lytical chemist in general practice, the atomic system has the 
tangible advantage of requiring a much smaller stock of standard 
solutions. But for a manager or foreman of some department in 
a chemical manufactory, who has to repeat say one or two deter- 
minations continually, we are old-fashioned enough to prefer the 
empirical system. 
We find in Mr. Sutton’s present edition a careful notice of the 
new alkalimetric indicators which have been introduced, with 
more or less success, in place of litmus. He gives the preference 
to Poirrier’s “ Orange 3,” as being entirely unaffected by car- 
bonic acid or sulphuretted hydrogen. Hence by its means 
samples of soda-ash, &c., can be titrated in the cold. Ammonia, 
also, does not interfere with its action, a merit not shared by 
phenol-phthalein. 
Taken as a whole Mr. Sutton’s work has no rival in the 
English language, and the present edition, being a distinct im- 
provement on its predecessors, will give correspondingly greater 
satisfaction. 
Magnetism and Electricity. An Elementary Text-Book for 
Students. By R. Wormell, D.Sc., Head Master of the 
City of London Middle-class Schools. London : Thomas 
Murby. 
The production of a good elementary text-book in any department 
of Science is no easy task. The fullest knowledge of the subject- 
matter is, in itself, far from sufficient. There is also required an 
acquaintance with the art of presenting subjects to the mind of 
the pupil. Hence we are beginning to find that such manuals 
should be written by men who, in addition to the requisite scien- 
tific mastery, possess the experience of the practical educationist. 
The treatise before us is drawn up from this double point of view. 
In the outset it makes exceedingly small demands upon the 
pupil’s knowledge ; but by a series of experiments, at first ex- 
ceedingly simple and easy, he is gradually led to a comprehension 
of the principles of electricity and magnetism, and to an under- 
standing of natural laws. 
We note with pleasure that the book — or rather the course of 
teaching for which the book serves as manual — is distinctly in- 
tended to be practical. The lecture experiments given in the 
