130 PROCEEDINGS OF SECTION B. 



Cannel oil in my experience is troublesome to purify, yielding 

 much tar (poliminerized acetelenes, etc.) to sulphuric acid. 



Shale is very rarely used alone for making gas, but it is so used 

 for the gas for the railway carriages on our Government I'ailways. 

 I tried to procure a sample of the tar but found that unfortunately 

 it could not be kept separate from the tar from bituminous coal, 

 from which gas is also made. The mixed tar was just heavier 

 than water and particularly mobile for a tar. Subjected to dis- 

 tillation, the process being carried so far that the residue in the 

 retort set to a rather hard pitch on cooling, it gave a distillate 

 wholly lighter than water. This distillate treated by reagents 

 gave the following percentages by bulk : — 



8.5 per cent to concentrated sulphuric acid — basic bodies 



and polyminerized acetelins. 

 31.9 per cent, sodium hydrate — phenols — and conjugate acid 



bodies formed by previous treatment with acid. 

 46.7 per cent, to nitric acid — aromatic hydrocarbons and 



olefins — 

 12.7 per cent, unattacked — paraffins. 



99.8 



As the shale used gives on low temperature distillation a refined 

 product containing paraffins to olefins in the ratio of 3 to 7, the 

 12.7 per cent above would give 29.6 per cent, of olefins which 

 added to 12.7 gives 42.3 per cent, of fatty hydrocarbons, and 

 substracted from 46.7 gives 17.1 per cent, of aromatic. If we 

 consider that the amount of phenols extracted by soda from 

 coal tar is about 6 per cent., and this added at the same rate 

 to the 17.1 per cent of aromatic hydrocarbon, would give 18.2 

 per cent of coal tar hydrocarbons, and we would then have 18.2 

 coal hydrocarbons to 42.3 of fatty or shale hydrocarbons, which is 

 in the ratio of 1 to 2.32. I am informed by Mr. Inspector Mitchell 

 that the quantities of material used in the gas works are 9^ tons 

 of Newcastle coal and 7f tons shale per week, and as coal gives 

 approximately 10 gallons of tar per ton, whilst shale averages 

 about 27 gallons, this would give the following i"atios : — 



Coal to shale as ... 1 : 0.82 

 Coal tar to shale tar as 1 : 2.29 



which shews a tolerably close approach to the ratio of hydrocarbons 

 actually found. In this only the more stable hydrocarbons which 

 have been taken into consideration, but, look at the matter how 

 we may, there seems no doubt that the fatty hydrocarbons remain 

 true to their type, and a,re much less readily converted into the 

 higher carbon aromatics than is usually assumed, under the con- 

 ditions of high temperature distillation as carried out on a large 

 scale. This is further shewn in the fact that although numbers 



