AMEKICAN INSTITUTE. 431 



witli paints mixed with this coal essence, dried quickly, and the smell dis- 

 appeared more rapidly than when turpentine was used. The introduction 

 of this into general use would be of great importance commercially speak- 

 ing. 



By simple distillation we obtain from bituminous coal a very fine oil for 

 burning in lamps, and by a second process, a much heavier product, admi- 

 rable for lubricating machinery, particularly if mixed with a saponified 

 animal, or fish oil. 



A very fine oil may be obtained by mixing sulphuric and nitric acid 

 with coal naphtha, which oil when exposed twelve hours to the action of 

 oxygen, becomes a crystalline solid, and if this is permitted to come in 

 contact with potassa, both in aqueous and alchoholic solution, has a great 

 analogy with the oil of bitter almonds. Coal oil obtained by the distilla- 

 tion of coal tar, mixed with a corresponding bulk of water, forms an admi- 

 rable fuel, and when passed through a nozzle perforated with small holes, 

 gives intense heat ; when rectified, it is extensively used for dissolving 

 India rubber, in making the vaimish of water proof cloth, and likewise for 

 burning in lamps, peculiarly constructed for the purpose. 



Coal oil separated from the thick tar, yields first the light essential oil ; 

 and afterwards a denser oil, .by progressively increasing the heat, tructuous 

 oil, fit for lubricating and greasing will be produced. There will be left 

 in the cucurbit a liquid tar, which may be converted into black grease by 

 mixing it with caustic soda ; after stirring this product at a temperature of 

 eighty-five degrees Fahrenheit for three hours, saponification takes place, 

 and parafiinised grease is produced. 



The heat for the production of oily matters must on no account be car- 

 ried beyond 600 degrees Fahrenheit, if it is, all the gas will be immedi- 

 ately converted into carbonated hydrogen and carbonic oxide, to the injury 

 of the hydro-carbonated and hydro-carburetted liquids. Seven gallons of 

 coal oil mixed with one gallon of turpentine, and stirred until thoroughly 

 incorporated, makes not only a good lubricating oil, but a safe burning oil. 



If you fill an air-tight vessel with water, overlying a small quantity of 

 the oil of coal tar, you may place in it flesh, birds with the feathers on, or 

 any other thing you may feel disposed to preserve for an indefinite period of 

 time, and success will attend the operation, so long as they remain immersed 

 in the water, which becomes charged with the vapor of the oil evaporating 

 at the ordinary temperature. I am led to believe that Breckenridge coal, 

 found in Kentucky, yields a superior oil for lubricatmg purposes. 



Various other products of coal when distilled, are turned to account ; 

 from the ammoniacal liquor, muriate of ammonia is manufactured ; 400 lbs. 

 of coal aff'ord 34 lbs. of coal tar, which again contains in 200 lbs. 52 lbs. of 

 coal oil, 96 lbs. of pitch. I have employed the tar as paint, with the view 

 of preserving wood, and found to my surprise, as it was highly recom- 

 mended, that a more injurious compound cannot possibly be used ; it will 

 completely destroy a shingle roof in five years, that would last thirty-five 

 without its use. I have likewise used the pitch, but consider it infinitely 



