of Heat and Pressure upon the Paraffins. 



187 



These numbers agree perfectly with those obtained by Anderson many 

 years ago* from analysis of a paraffin identical in origin and melting- 

 point (45°-5) with that employed by us. Dr. Anderson found for the 

 substance the composition : — 



Carbon 854 



Hydrogen 15*1 



100-2 



A sample of paraffin from peat, melting at 46 °- 7, gave : — 



I. II. Mean. 



Carbon 84-95 85-23 85-09 



Hydrogen 15-05 15-16 15-10 



100-00 100-39 100-19 



In the process of conversion we replaced the bent glass tube above 

 described by an apparatus consisting of two cast-iron mercury bottles 

 connected together by a bent iron pipe, in which were fixed a stopcock 

 and pressure-gauge. One of the bottles was charged with the paraffin, 

 and was heated over an ordinary coal fire, the heat being so regulated 

 that a pressure of 20 to 25 lbs. was maintained in the apparatus through- 

 out the operation. The volatilized products distilled over into the 

 second bottle, which acted as a condenser. In about four or five hours 

 the operation was concluded, and the distillate had the appearance of a 

 magma of oil, and of apparently unaltered paraffin. This mixture melted 

 at a comparatively low temperature, the warmth of the hand being suffi- 

 cient to render it completely liquid. 



Three and a half kilograms of the paraffin yielded about 4 litres of 

 liquid hydrocarbons. On distillation the mixture commenced to boil at 

 18°, but the quantity coming over below 100° was comparatively small ; 

 by far the greater portion boiled between 200° and 300°. A preliminary 

 separation showed that the 4 litres were approximately made up of 

 hydrocarbons boiling : — 



litres. 



I. Below 100° 0-3 



II. From 100-200° 1-0 



III, From 200-300° 2-7 



4-0 



A considerable quantity of substance, which could not be distilled 

 within the range of the mercurial thermometer, remained in the retort, 

 and solidified on cooling (see section 12). Each of the portions was then 

 submitted to a systematic fractional distillation. 



* Rep. Brit, Assoc, 1846, 

 vol. xxt, n 



