PETROLEUM. i 53 



haying only a slight odor like that of fat-oils, while the hydrocarbons 

 that are condensed after passing over have a very offensive odor. 

 The very last distillates from all of the destructive distillations are 

 called " cokings," and are distilled by themselves, yielding mainly 

 crude lubricating oil. The carbon separated in the stills contains 

 some caustic soda, which can be obtained as carbonate by burning 

 the carbon aud lixiviating the ashes. The sulphuric acid used in 

 agitating the oils is known as " sludge," and is sometimes sold to the 

 makers of superphosphate of lime, although it has been occasionally 

 successfully reconverted into oil of vitriol. The following list in- 

 cludes the commercial products which have been made from petro- 

 leum, being those already mentioned, with the exception of cymo- 

 geue, which is distilled from gasolene, and condensed by a pump: 



1. Cymogene, specific gravity 110 Beaume ; boils at 32 F. (0 C.) ; 

 used in ice-machines. 2. Phigolene, sp. gr. 100 B. ; boils at 65 F. 

 (18.3 C.) ; extremely volatile, producing by its rapid evaporation a 

 temperature of 19 F. ; used as a local anaesthetic. 3. Gasolene, 

 sp. gr. 97, 90, 88, and 86 B., as required by the market. The very 

 light gasolene is ordered in small quantities, probably for ice-machines. 

 The others are used in gas-machines, for which they are admirably 

 adapted, and for various exceedingly dangerous lamps and stoves 

 designed for their combustion. 4. Naphtha, sp. g. 70 to 76 B. ; 

 boils at 180 F. (27 C), when of 70 gravity ; used in manufacture of 

 oil-cloths, cleansing, as a solvent for paraffine, etc. ; sometimes fraudu- 

 lently mixed with the higher-priced illuminating oils, or with crude 

 petroleum, to be again sold to the refiner ; also sold, under various 

 names, as a burning-fluid, notwithstanding the certain danger attend- 

 ing its use. 5. Benzine, sp. gr. 65 to 62 B. ; the boiling-point for 

 65 B. is 300 F. (149 C.) ; used in making paints and varnishes. 9. 

 Illuminating oil {kerosene), sp. gr. 45 to 50 B. ; boiling-point for 

 45 B. is 350 F. (177 C). " Astral " oil and " mineral sperm " are 

 particularly safe varieties, freed with care from explosive compounds. 

 7. Lubricating oil. il Neutral" lubricating oil has a specific gravity 

 of 29 B., and boils at 575 F. (301.5 C). 8. Paraffine, sp. gr. 0.87 ; 

 fusing-point for commercial paraffine about 110 to 150 F. (43.3 to 

 65 C.), according to its purity ; boiling-point about 698 F. (370 C.) ; 

 used for making water-proof fabrics, candles, lubricators, matches, 

 chewing-gum, etc. 



The refined illuminating oil should be free from moi-e volatile 

 compounds, which cause it to give off vapors that explode when 

 mixed with air and ignited. Dr. White, President of the New Orleans 

 Board of Health, found that, on adding to oil which " flashed " at 

 113 F. one per cent, of naphtha, the mixture flashed at 103 ; with 

 two per cent, at 92 ; with five per cent, at 83 ; with 20 per cent, the 

 oil itself burned at 50 (" Report on Petroleum to New York Board 

 of Health," Dr. C. F. Chandler, 1871). Dr. Chandler has found that 



