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POPULAR SCIENCE REVIEW. 
dye, which may be used either alone for dyeing yarns or threads and 
piece goods, or be treated with suitable chemical reagents for varying 
its hue as desired. One hundred kilogrammes of naphthaline are boiled for 
a few hours in an acid solution composed of 200 kilogrammes of water and 
20 kilogrammes of nitric acid at 30° Beaume. The naphthaline must 
be kept well stirred while dissolving in the boiling water and acid, and 
the agitation must be maintained until the mixture has become cold. 
The mother liquor is next drawn off, and the naphthaline will then present 
the appearance of brown crystals. These crystals are now washed in 
cold water to remove the acid. In order to obtain a yellow solution of 
colouring matter, the crystalline product is to be treated with boiling water, 
to which is added 5 kilogrammes of liquid ammonia. The solution thus 
obtained is to be filtered, and subsequently evaporated into a concentrated 
state. The concentrated solution must in like manner be filtered, and 
when cold it will be ready for use. 
Manufacture of Blue and Violet Colouring Matters. — Messrs. 
Poirrier & Chappat , patentees. — For the purposes of this invention, the 
aniline reds (known in commerce under the names of fuchsine, roseine, 
magenta, and under other names, and, chemically, as being different 
salts of rosaniline) are treated with naphthylamine — a substance which 
is derived from naphthaline, as aniline is derived from benzine. 
Manufacture of Blue Colours. — Mr. A. P. Price , patentee. — The 
main feature of this invention consists in the employment of acetates, 
citrates, succinates, racemates, malates, valerinates, carbolates, benzoates, 
cinnamates, tartrates, and oxalates of potash, soda, and ammonia, in 
conjunction with aniline, roseine, and rose-aniline, in the production of 
blue colours. 
Rendering Cloth and Paper Transparent and Waterproof. — 
Mr. E. T. Hughes , patentee. — The objects here in view are effected by 
the use of a composition composed of one part by measure of linseed oil, 
one part of india-rubber cement, and six parts of benzine. This, for 
most purposes, constitutes the best mixture ; but for a preparation of 
tracing-cloth and tracing-paper of close texture, it may be advisable to 
use an additional proportion of benzine, to avoid producing a gloss on 
the outside, and also to avoid filling the pores of the paper too full to 
retain the ink and colours which may be applied. 
Aromatic Vinegar. — Mr. H. A. Boneville , patentee. — The patentee 
claims the use ©f the ethers, amyl-acetic, ethyl-acetic, and methyl-acetic, 
as the base of a new aromatic and at the same time hygienic vinegar, 
which may be used for removing stains from stuffs of all kinds, without 
altering their shades, whether employed alone, or mixed together in equal 
parts, dissolved or not in absolute alcohol, acidulated with acetic acid 
for reviving certain colours, or aromatized by the addition of certain 
perfumes. 
Voltaic Belts. — Mr. R. A. Brooman, patentee. — In constructing belts 
and bandages in accordance with these improvements, they are composed 
of a bi-metallic core, consisting of plates, strips, or blades of metal, one 
electro-positive to the other, such as copper and zinc, forming a voltaic 
battery, juxtaposed or placed one against the other, and covered with 
