130 
THE YOUNG SCIENTIST. 
size. Any rising air bubbles must be re- 
moved, and the mass is then allowed to 
become cold, when it will form an elastic 
mass, a little firmer than printer's rollers. 
Other formulae substantially the same, but 
with slight changes in the proportions, 
and the addition of various unimportant 
ingredients, have been published. In any 
case the resulting mass has the property 
of absorbing to the depth of perhaps 
1-64 inch writing or tracings made with 
certain kinds of ink, particularly aniline- 
inks. Any aqueous ink would answer, 
but it is necessary to use one which is 
made of a very persistent color. The 
writing desired to be multiplied is written 
upon a sheet of paper with the special 
ink described hereafter ; after the ink is 
completely dry, the sheet is laid on the 
moistened gelatine-surface (writing down), 
and gently rubbed over with the hand. 
After a short time (about half a minute), 
the paper is removed and laid aside. 
Fresh paper being ready, a sheet is laid 
upon the writing, and the hand gently 
rubbed over the back, when a clear and 
complete copy of the writing will be found 
on the paper. This may be repeated from 
sixty to a hundred times, according to the 
quality of the ink, and the experience of 
the operator. When no more copies are 
wanted, or when the ink is exhausted, the 
surface is washed off with a sponge and 
cold water. Any traces of the ink left in 
the mass, after thoroughly washing, will 
not interfere with the next copy. When 
necessary, the mass in the tray may be 
remelted. 
The ink may be prepared as follows : 
Violet : methyl-violet, 2 : dilute acetic 
acid, 2 ; water, 4 parts. 
Or, red : fuchsine, 2 ; alcohol, 1 ; water, 
8 parts. 
Or : Mix 5 parts of any desirable aniline 
color, 5 of alcohol, 5 of mucilage, and 35 
of water in a flask, heat until dissolved, 
and after 24 hours strain through flannel 
or wool. The selection of aniline-colors 
is difficult, as many of them are largely 
composed of dextrin, which dries up or 
makes the solutions thick. The best 
aniline color, according to E. Stormer. is 
the Violet de Paris de Poirrier. 
This apparatus is specially valuable to 
microscopists and naturalists, who require 
a few dozen copies of exchange lists or de- 
scriptions of apparatus. To have such 
lists printed is a process altogether too 
expensive, while few are able to afford 
electric pens and similar apparatus. The 
simple contrivance which we have de- 
scribed, and which may be made at an ex- 
pense of a few dimes, answers every pur- 
pose. 
A New Form of Sprinkler. 
A SIMPLE method of distributing a 
liquid in fine spray, is one much 
needed in many operations. The old- 
fashioned sprinkler with its" nozzle per- 
forted with numerous holes, is probably 
the oldest device of the kind, but it is a 
very imperfect one. The method used by 
those who practice " spatter- work " gives 
finer spray, but lacks the ability to give 
sufficient quantity to moisten articles, 
such as paper, cloth, etc., thoroughly. 
One of the most perfect contrivances of 
the kind that we have seen, consists of 
an application of the atomiser, and is 
in use amongst silk-manufacturers for 
moistening the silk during certain pro- 
cesses. It is very simple and easily made, 
as will be evident from the accompanying 
engraving. It consists of a tin vessel 
ATOMIZER rOK SPEINKLING. 
across the top of which is fixed a tube 
through which air may be blown. The 
tube is supported by the edge of the ves- 
sel and also by a tin plate which covers 
half the vessel next the mouth of the 
operator. The point of the tube ends 
about an inch from the opposite side of 
the vessel, and on a level with the edge. 
When the vessel is filled with water, and 
a blast of air is sent through the tube, the 
water is lifted up and scattered in the 
finest spray. As the liquid sinks in the 
vessel, the apparatus is tipped so as to 
bring the water up to the edge, and in this 
