K. DOMESTIC AND HOUSEHOLD ECONOMY. 443 



water as will dissolve it, then headed, and the liquids thor- 

 oughly mixed by shaking the barrel, which should then be 

 filled to the bung Avith water, and allowed to remain for 

 from twelve to fourteen days; then, after withdrawing the 

 discolored liquid, it should be well rinsed and filled with pure 

 water and allowed to remain several days, when it will be 

 fit for use. Other wooden utensils may be treated with a 

 similar solution of soda. 8 C.Nov. 26, 1874, 422. 



LAMP FOR BURNING NITRIC OXIDE GAS. 



The brilliancy of the light produced by the combustion 

 of nitric oxide gas, after mixture with a few drops of sul- 

 phide of carbon, has been known for some time, and its ap- 

 plication to photographic purposes suggested ; but it is not 

 until recently that Messrs. Delachanal and Mermet have con- 

 structed an apparatus by which it can be made practically 

 available. They use a lamp made of a pint bottle, having 

 two openings through the cork, and filled with fragments of 

 some porous substance, as sponge, coke, or pumice, for the 

 purpose of imbibing the sulphide of carbon. A tube, reach- 

 ing w 7 ithin one fourth of an inch of the bottom, passes through 

 one opening in the cork, and a larger one through the other 

 opening. This is about eight inches long, and may be of 

 glass or metal, and is closely packed around w 7 ith iron-scale. 

 The object, like that of the gauze in the safety-lamp, is to 

 prevent the return of the flame into the bottle, and its con- 

 sequent explosion. The nitric oxide gas is passed into the 

 bottle through the first-mentioned tube, and the gaseous 

 mixture is conducted by a rubber tube to a kind of Bunsen 

 burner, the air-holes of which are closed, and which is fur- 

 nished with a small conical valve to regulate the flow of 

 gas. This burner is also filled with iron-scale. The nitric 

 oxide gas is produced in the cold by Sainte-Claire Deville's 

 method, by the action of a mixture of nitric and sulphuric 

 acids upon metallic iron. With an apparatus of quite mod- 

 erate dimensions a dazzling flame, not less than ten inches 

 in height, can -be obtained, abundantly sufficient for the pur- 

 poses of photographic work. It has been estimated that the 

 photographic power of the lamp is superior to that of mag- 

 nesium, is twice as great as that of the oxyhydrogen light, 

 and three times as ere at as that of the electric light. Fur- 



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