108 Notices of Books. (January, 
been selected to a great extent ‘‘on account of their practical 
utility.” In other words, the work has a technological character, 
which, without unfitting it for students of other classes, makes 
it particularly suited for artisans. It is divided into five sections. 
The first of these is a full and carefully compiled treatise on 
chemical manipulation, as far as qualitative analysis is concerned. 
The instructions on the use of the balance are admirable, and it 
would not be easy to point out any necessary precaution which 
the author has omitted to press on the attention of his readers. 
Indeed it might be suggested that mention of the method of 
weighing by vibrations, with the accompanying mathematical 
formule, are not somewhat out of place in such a work. ‘There 
is also an attempt at determining by algebraical calculations the 
amount of wash-water, and the minimum number of washings 
required to bring any precipitate to a state of purity. The use 
of the filter-pump is explained at full length. The action of the 
solvents employed upon the apparatus in digestions, evapora- 
tions, &c., is pointed out as a possible, though generally 
overlooked, source of error. In short, not merely students—in 
the common sense of the term—but not a few chemists of old 
standing might find their advantage in a careful perusal of this 
section. 
The remainder of the work consists of a graduated series of 
examples in simple gravimetric analysis; of a section on 
volumetric operations; of an account of the methods used in 
the valuation of ores, minerals, and industrial products; and 
lastly, of a special section on organic analysis. 
Turning to the assay of pyrites, we find that the author directs 
the sulphur to be oxidised by means of chlorate of potassa, and 
not hydrochloric acid—as a certain standard work advises, with 
the ordinary result of a small explosion—but nitric acid, which 
works safely and well. The subsequent expulsion of the nitric 
acid, the rendering all silica insoluble, the removal of the last 
traces of sulphate of lead which may possibly be present, are all 
duly pointed out as needful. The addition of a little tartaric acid 
to prevent the precipitation of iron, along with the sulphate of 
baryta, is a sound precaution. We have seen precipitates of 
sulphate of baryta which, though thrown down from decidedly 
acid solutions, had a very tawny look. The digestion with 
acetate of ammonia to remove traces of nitrate of baryta which 
may remain entangled in the precipitate is also useful. 
Turning to the separation of phosphoric acid from iron and 
alumina, we find that the author recommends the tin process 
(Reynoso’s) to the exclusion both of the bismuth and of the 
molybdenum method, the latter of which we certainly prefer, 
whenever a comparatively small amount of phosphoric acid has 
to be determined in prescence of a large proportion of iron and 
alumina. The molybdenum process is, however, described and 
recommended for the determination of phosphorus in irons and 
ee eo 
