178 
VARIETIES. 
between the poles and the keeper it still supported a weight equal to that 
borne by the best magnets hitherto made — Ibid. 
On a mode of distinguishing Paper made from Linen and Cotton. By M. 
Cesareca. — M. Cesareca of Havanna, states, in this communication, that the 
employment of caustic potash or soda is the best mode of ascertaining whe- 
ther linen or cotton has been employed in the manufacture of any kind of 
paper and recommends the use of the following process as a means of read- 
ily ascertaining the difference : — Boil the paper in a mixture of two ounces 
of caustic soda or potash, in a quarter of a pint of distilled water ; the paper 
made with linen remains unacted upon, whilst that made of cotton is re- 
duced to a pulpy mass. This alkaline liquor also furnishes a means of 
distinguishing cotton and linen fabricks, and their admixtures. — Ibid. 
Protection of Electrifying Machines from Dampness. — To protect electrifying 
machines from dampness, Munch recommends us to draw from the centre 
of both of the surfaces of the glass-disk towards the periphery, a line with 
grease, and by which the disk on being turned, becomes covered with a thin 
coating of fat, and is thus protected against contact with damp air. The in- 
sulating glass feet of the machine may also be thus protected by drawing 
on them a line with grease, and spreading it with a cloth. The machines 
can then be worked even in damp weather. — Pharm. Central Blatt, 1850. 
No. 12. — [The same effect is obtained by covering the glass surface with a 
film of some volatile oil, as oil of cloves. — Ed. Pharmaceutical Journal.'] — 
Ibid. 
Marbling Materials. — Four parts of resin and one part of wax having been 
previously melted together, six parts of a hot solution of glue are added, and 
after this four parts of powdered alum, with twelve paits^of powdered gyp- 
sum. Color the composition to pleasure, stir in a quantity of refuse silk 
\Seidenabfalle~] and pour in moulds. The surface assumes then a veiny ap- 
pearance. The walls of rooms may thus be decorated, if the cement be 
mixed with the refuse of silk instead of with cow-hair — Ibid, from Pharm. 
Central Blatt, 1850, No. 12. 
Telegraphs in Germany. — Within the last four months, through the activity 
of the minister of trade, no less than 1000 miles of telegraph have been 
opened in Austria, making the total mileage about 2000, of which about one- 
quarter has the wires laid underground on the improved system. Another 
1000 miles will be ready by next year. The telegraph now works from 
Cracow to Trieste, 700 miles. On the 1st October the new telegraph union 
between Austria, Prussia, Saxony, and Bavaria comes into operation under 
a uniform tariff, which is one half the former charges. The progress will 
be looked upon with interest by the commercial public here, who are very 
