408 Progress in Science. [July, 
with Digny’s ink-roller. The battery is a form of Daniell’s, arranged by 
Sergeant Mathison, R.E. 
TECHNOLOGY. 
According to Dr. J. M. Maisch, an excellent liquid glue about the consistency 
of molasses is made by dissolving glue in nitric ether; this fluid will only dis- 
solve a certain amount of glue, consequently the solution cannot be made too 
thick. It is much more tenacious than that made with hot water. By adding 
a few pieces of caoutchouc, cut into scraps the size of buckshot, and allowing 
the solution to stand a few days, frequently stirring, it will resist dampness 
twice as well as glue made with water. 
In a long interesting paper on the alloys now frequently employed for 
making imitation jewellery, known as Abyssinian gold, Talmi gold, &c., 
Dr. C. Winkler points out that the alloy is not galvanically gilt, but is plated ; 
that is to say, a very thin sheet of gold is made to adhere to a yellow metal 
by rolling them together, and afterwards shaping, moulding, and chiselling by 
means of steel tools, the amount of gold varying from 1°03 to 0'03 per cent. 
As regards wear and tear, the author admits that, by careful plating, these 
articles really answer well. 
The use of inks of a similar composition to that now generally employed 
appears to be of more ancient date than is generaily supposed, for on 
examining a manuscript of the year gto, and belonging to the papers of the 
Cluny Abbey (Paris), Dr. Balard found that the ink it was written with was 
similar in composition to that now in use: it appears that MM. Coupier and 
Collin have succeeded in preparing an ink which is not aged upon by nitric 
and hydrochloric acids, chlorine, or bromine; it is not, however, quite proof 
against alkalies. 
The very common use, especially in England, of soda for washing linen is 
very injurious to the tissues, and, moreover, has eventually the effec of 
yellowing it. Dr. Quesneville states that in Germany and Belgium the 
following mixture is now extensively used :—2 lbs. of soap are dissolved in 25 
litres of water as hot as the hand can bear it; three large-sized tablespoonfuls 
of liquid ammonia and one spoonful of best oil of turpentine are then added. 
These fluids are incorporated rapidly by means of beating the soap-suds and 
other fluids with a small birch-broom. The linen, &c., is then put into 
the liquid and soaked for three hours, care being taken to cover the washing- 
tub with a closely-fitting wooden lid; by this means the linen is readily 
cleansed, requires very little rubbing, and there is also a saving of time and 
fuel. Ammonia affects neither linen nor woollen goods, and is largely used as 
washing-liquor in the North of England. 
The following method is recommended by M. Méne for dyeing veneer wood. 
The wood is first steeped for twenty-four hours in a solution of caustic soda, 
and boiled with it for half an hour. It is then washed, to remove all the 
alkali, and having become as soft as leather and equally elastic, as well as 
capable of absorbing dye-stuffs, it is immersed for twenty-four hours, first in a 
decoction of logwood, and then, after having been superficially dried, into a 
boiling solution of sulphate of iron. When required to be yellow-dyed, it is 
immersed in a solution of picric acid to which ammonia is added. Wood, 
after steeping in soda, may also be dyed with coralline. The dyes are fast, 
stand varnishing, and thoroughly penetrate through the whole of the wood, 
which, after drying, may be sawn and veneered. 
C. Daniel has described a method of painting with oil paints upon tin-foil 
stretched uniformly on sheets of plate glass until the painting and varnishing 
are finished. The tin-foil thus prepared is used instead of paper-hangings, and 
for decorative purposes ; gilding can also be applied. 
A rapid dryer for oil-paints and varnishes is formed by dissolving in 100 
parts of water by the aid of heat, 12 parts of best shellac and 4 parts of 
borax; pouring the solution, after cooling, into bottles, which should be 
well corked. According to M. Méne, this solution is mixed with oil of turpen- 
tine, and added to oil-paints; the liquid may also be employed as a varnish. 
