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3. Method of Browtiing Iron. 

 [Communicated by Mr. John DuDtze, of New- Haven.] 



Nitric acid, - - - - i ounce. 



Sweet spirits of nitre, - - | do. 



Spirits of wine, - - - 1 do. 



Blue vitriol, .... 2 do. 



Tincture of steel, - - - 1 do. 



These ingredients are to 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 barrel 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 a third 

 time, (if requisite,) by which the barrel will be made of a 

 perfectly brown colour. It must then be carefully brushed 

 and wiped, and immersed 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 may be destroyed, and the 

 impregnation of the water by the acid neutralized. 



The barrel, when taken from the water, must, after being 

 rendered perfectly dry, be rubbed smooth with a burnisher 

 of hard wood, and then heated to about the temperature of 

 boihng water ; it then will be ready to receive a varnish 

 made of the following materials :• — 

 Spirits of wine, one quart, 

 Dragon's blood pulverized, 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 and- 

 glossy appearance* 



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