318 
MISCELLANY. 
Mode of dividing Plates of Zinc. By M. Waidele. — It is frequently 
a subject of great difficulty to divide plates of cast zinc for use in gal- 
vanic batteries. The following is a simple and ready method of ac- 
complishing this end. Grease the plate over by means of a rag and 
a little tallow ; with a pointed instrument draw a line in the required 
direction of the cut, so as to remove the grease from that spot, and 
penetrate slightly into the metal • pass a little dilute sulphuric acid 
over this line by means of a feather, and then let a drop or two of 
mercury fall on the same spot ; the zinc soon becomes amalgamated in 
the direction of the line, and through its entire thickness. A slight 
blow, properly given, will cause it to break. — Chem. Gaz. from Revue 
Scient. 
Preparation of Ferridcyanide of Potassium. By Dr. Riegel. — It has 
recently been recommended, in order to prevent the formation of the 
well-known yellowish-green body in the preparation of the red 
prussiate of potash, to pass the chlorine obtained from 50 grms. salt 
with manganese and sulphuric acid into a solution of 50 grms. of the 
yellow ferrocyanide in 200 grms. water. The author could not obtain 
any satisfactory result by this method ; he therefore recommends, 
when the formation of the body cannot be avoided, to allow the liquid 
to evaporate in a very tall vessel, when the green body is constantly 
deposited at the bottom of the vessel, and can readily be removed 
mechanically by repeated recrystallization. — Ibid, from Jahrb. fiir 
Prakt. Pharm. 
Manufacture of Lucifer-Matches without Sulphur. By R. Bottger. — 
The author recommends the following composition for the preparation 
of lucifer matches: — 4 parts phosphorus, 10 parts nitre, 6 parts gela- 
tine, 5 parts red lead or ochre, and 2 parts smalt. The gelatine is 
soaked in a small quantity of water for 24 hours, the jelly conveyed 
into a mortar and warmed until it has melted, when the other in- 
gredients are introduced, constantly applying heat, but not above 167°, 
until the whole forms a perfectly homogeneous mass, which cannot 
be drawn out into threads. To make lucifer-matches with this mass, 
which continue to burn after ignition, without any coating of sulphur, 
the extremities of the matches are held for a few seconds against a 
plate of iron, in order to carbonize them superficially; they are then 
dipped into very hot melted wax, the excess shaken off with a jerk 
of the arm, and dipped into the above composition.— -Ibid, from Phys. 
und Chem. Vorlesung. 
