CHEMISTRY. 237 



first part of the distillation is carried on by the aid of high pressure steam 

 being passed through the spiral worm until the most volatile parts, among 

 which is eupion, are driven off; the steam so applied should not be less 

 than fifty, and not more than sixty pounds' pressure to the square inch. 

 Fifty pounds' pressure is found to answer in practice. The distillation is 

 then continued, aided by a gentle fire placed underneath the still, until one- 

 fifth part of the contents of the still have passed over into the receiver, and 

 that one-fifth part is found to be eupion nearly pure. The contents of the 

 receiver are then discharged into another vessel, and kept separate from the 

 further distillation, which is continued, the fire being urged and the steam 

 supplied to the still, until the remaining ninety-five parts, or nearly so, have 

 passed over ; these will be impure eupion, that is, eupion combined with other 

 carbo-hydrogens, holding a large quantity of paraffine in solution, and called 

 eupion oil, the production of which is the object of the second course of 

 distillation. During the latter part of this distillation, large quantities of 

 paraffine and a small part of pyrolaine pass over ; and great care must be 

 taken to keep the condensing pipes at a temperature of about 90 degrees 

 Fahrenheit at the middle of the distillation, gradually raising it to about 120 

 degrees Fahrenheit towards the end. This object is obtained by means of 

 the steam pipe passing into the water contained in the refrigeratory cistern 

 surrounding the condensing pipes. There will remain a residuum in the body 

 of the still after the charge has been worked off, containing a large quantity 

 of paraffine ; this is placed in an iron retort (similar to those used in gas 

 works), and is- heated to a low red heat ; paraffine vapors pass off, and are 

 condensed by means of a straight iron condensing pipe of at least three inches 

 in diameter, issuing from the interior of the retort, and maintained at a tem- 

 perature of about 120 degrees Fahrenheit, by passing it through a cistern of 

 hot water kept at a uniform temperature of 120 degrees Fahrenheit, or there- 

 abouts, throughout the distillation. The impure paraffine thus produced is 

 mixed with the eupion oil before mentioned, or it may be purified. 



Treating Bituminous Mineral Products for the Extraction of Oils, &c. M. 

 Barry, of France, has recently patented some improvements hi the treatment 

 of bituminous shale, Boghead mineral, and other schistose bodies, to obtain 

 various commercial results therefrom. The produce is, highly rectified 

 mineral oil, mineral oil for lighting, fat unctuous paraffine oil, and mineral 

 grease. The inventor uses retorts for decomposing the schistose bodies, and 

 a receiver. The pipes which conduct the gases from the retort, enter partly 

 into the receiver, which is placed at some distance from the retorts ; a con- 

 denser, provided with refrigerating tubes, condensing the raw oils and ammo- 

 niacal waters. Purifiers formed of wooden cases, lined with lead, and pro- 

 vided each with an agitator, are employed to place the oils, after their separa- 

 tion from the thick tar, in contact with 5 per cent, by weight of sulphuric acid. 

 The matters must be agitated for about three hours, then left to settle down, 

 and drawn off into a second purifier, placed under the first, where they have 

 added to them about 5 per cent, by weight of caustic soda, or a sufficient 

 quantity of lime water, and the whole is to be well stirred for several hours, 

 and then allowed to settle. The distilling apparatus for the raw oils, is com- 



