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168 . Method of Browning Iron. 
| 3. Method of Browning Iron. 
[Communicated by Mr. John Duntze, of New-Haven.| 
- Nitric acid, - - 4 ounce. 
Sweet spirits a nitre, Lo - Ee: dos 
Spirits of witli menses: * ol 
Blue vitriol, -. - - . 2 
Tincture of ateel, - 1 do. 
hes se ingredients are io be mixed, the vitriol having been 
previously dissolved in a sufficient quantity of water to 
make, with the other ingredients, one quart of mixture.— 
Previously to commencing the operation of browning a gun 
barrel, it is necessary that it be well cleaned from all grea- 
siness and other impurities, and that a plug of wood be put 
into the muzzle, and the vent well stopped. The mixture is” 
then to be applied with a clean sponge, or rag, taking care 
that every part of the barre] be covered with the mixture, 
which must then be exposed to the air for twenty-four hours, 
after which exposure the barrel must be rubbed with a hard 
brush, to remove the oxid from the surface. 
This operation must be performed a second and Ps third 
time, -(if 8 gre by which the barrel will be made of a 
perfectly brown colour. It must then be cimesally Srattied 
and wiped, sha duattie teed in boiling water, in which a quan- 
tity of alkaline matter has been put, in order that the action 
of the acid upon the barrel m:y be destroyed, and the 
impregnation of the water by the acid neutralized. 
The barrel, when taken from the water, must, after being 
Leics perfectly dry, be rubbed smooth with a burnisher 
of hard wood, and then heated to about the temperature of 
ie vac; it then will be ready to receive a varnish 
made of the fallowig 2g eg _ 
Spirits of wine, one qua 
Dragon’s blood Se 8 three drams, 
Shell lac bruised, one ounce ; 
and after the varnish is perfectly dry upon the barrel, it 
must be rubbed with the burnisher to give it a smooth an 
ssy appearance. 
me 
