94 
SUMMARY OF CURRENT RESEARCHES. 
Browning Iron or Steel.* — A correspondent gives the following 
method for browning iron or steel to protect them from rust : — 2 parts 
of crystallised iron chloride, 2 parts of chloride of antimony, and 1 part 
of gallic acid are dissolved in 4 parts of water. The object is then 
smeared with the solution applied with a rag or sponge, and is al- 
lowed to dry in the air. The procedure is repeated several times until 
the colour is sufficiently dark. The object is then washed with water, 
dried, and the surface rubbed with boiled linseed oil. The antimony 
chloride should be quite neutral. 
* Centralztg. f. Opt. u. Mech., 1897, p. 4. See Zeitschr.f. angew. Mikr., iii. (1897) 
p. 118. 
