1872.] Notices of Books. 503 
arsenic, mercury, platinum, silver, gold, manganates, aluminum, 
and magnesium are described. ‘The various applications of the 
voltaic current to Electro-Metallurgy follow under this division. 
The preparation of potash- and soda-salts, the manufacture: of 
sulphuric acid, and the recovery of sulphur from soda-waste, 
of course occupy prominent places in the consideration of 
chemical manufactures. Soap manufacture will be found to 
include much detail. The technology of glass, stone-ware, 
limes, and mortars, will be interesting to the builder and 
engineer. The technology of vegetable fibres has been con- 
sidered to include the preparation of flax, hemp, cotton, as well 
as paper-making; while the application of vegetable products 
will be found to include sugar-boiling, wine and beer brewing, 
the distillation of spirits, the baking of bread, the preparation of 
vinegar, the preservation of wood, &c. Information is given in 
reference to the production of potash from sugar residues, the 
use of baryta salts, the preparation of sugar from beet-root, 
tanning, the preservation of meat, milk, &c. The preparation 
of phosphorus and animal charcoal are included in the technology 
of animal products. The preparation of the materials for dyeing 
have required much space. The final sections of the book are 
devoted to the technology of heating and illumination, the pro- 
duction of gas, coke, and tar from coals; the extraction from the 
tar of benzol, carbolic acid, aniline, anthracen, asphalte, naph- 
thaline; the preparation of tar colours, as rosaniline, aniline 
blue, Manchester yellow, Magdala red, alizarine, iodine green, 
picric acid, &c. 
The work is illustrated with 336 engravings. In presenting it 
to our readers we offer the latest improvements in chemistry, as 
applied to arts and industry, with the endeavour to merit the 
confidence of the manufacturer and the student. 
Health and Comfort in House Building. ByJ.Dryspae, M.D., 
and J. W. Haywarp, M.D. London and New York: E. and 
F.N. Spon. 1872. 
In this work we have most valuable practical suggestions as to 
the construction of houses with regard to warmth, comfort, and 
ventilation. Drs. Drysdale and Hayward, after devoting much 
time and thought to the subject, recommend that—in order to 
obviate any ill effects resulting from the free ingress of cold air 
into our rooms—a system of warming and ventilation be em- 
ployed, utilising the heat of the kitchen chimney by means of a 
syphon-shaft and foul-air chamber. The latter consists of an 
air-tight zinc drum, about 6 feet in diameter by 5 feet high, 
placed under the roof of the house, each room having a separate 
escape-tube to the drum. The expansion of the water is pro- 
vided for by a safety tube at the top of the circuit. This is the 
high-pressure system. The low-pressure system consists of a 
