200 Messrs. Thorpe and Young on the Combined Action 



to remove adhering oil as far as possible, and repeatedly recrystallized 

 from ether until the melting-point was unaltered. 



It melted invariably at 41°-5 and solidified at 40°-5 ; it could not be dis- 

 tilled within the range of the mercurial thermometer. 



It crystallized from ether in beautifully white satiny scales, and gave 

 the following numbers when burnt with oxide of copper in a stream of 

 oxygen : — 



0*3035 grm. gave 0-9590 grin, carbon dioxide and 0*419 grin, water. 



Carbon i 85-19 



Hydrogen 15-34 



100-53 



Action of bromine upon the solid paraffin melting at 41°-5. — A few 

 grams of the substance were dissolved in bisulphide of carbon, and four 

 minute drops of bromine added ; this small quantity of bromine sufficed 

 to colour the liquid strongly. On standing from 12 to 15 hours, the 

 colour appeared unaltered, and the solution was not decolorized after 

 heating from 60-70° for 12 hours. On heating the liquid to 150°, the 

 colour disappeared after a few hours ; and on opening the tube hydro- 

 bromic acid was evolved. About 10 drops of bromine were again added, 

 and the liquid reheated to 150° ; but no diminution in the red colour 

 of the solution was perceptible, although on opening the tube hydro- 

 bromic acid fumes were abundantly disengaged. This observation would 

 appear to indicate that the hydrocarbon melting at 41°*5 is a member of 

 the C n H 27l+2 series. 



Action of heat upon 41° K 5 paraffin. — Repeated crystallization from ether 

 having failed to alter the melting-point of this substance, and the behaviour 

 with bromine evidently indicating that it belonged to the marsh-gas series, 

 we considered that it would be interesting to study the combined action 

 of heat and pressure upon it. The details of the experiment have been 

 already given in section 1. After six distillations it was rendered com- 

 pletely liquid. It began to boil at about 40°, and about one sixth came 

 over below 100°, about one third between 100° and 200°, and the greater 

 portion of the remainder below 300° ; the small quantity remaining in the 

 retort solidified on cooling. 



In a second experiment the action of bromine upon the liquid hydro- 

 carbons was quantitatively determined : 



"Weight of liquid hydrocarbon taken 5-73 grms. 



„ bromine required before the liquid was reddened 30*7 „ 



The action of the bromine was very energetic, and it was necessary to 

 moderate the reaction by cooling the liquid. 



It is evident from these experiments that the solid paraffin (x C n H 2n+2 ) 

 had been split up by heat and pressure into a mixture of hydrides and 

 olefines. 



