548 



KEPOET 1880. 



The following table shows some of the leading distinctive characters of the 

 three liquids : — 



It is evident, therefore, that while shale naphtha resembles the petroleum pro- 

 duct in its general physical characters and its slight solvent action on pitch, it is 

 sharply distinguished from it by its reaction with carbolic acid. 



The burning oils from petroleum and from shale resemble each other very 

 closely. Neither product is miscible with absolute carbolic acid, but that from 

 petroleum gradually turns the acid vdolet and ultimately black. 



The dilt'erent behaviour of petroleum and shale naphthas with carbolic acid 

 suggested that they were not quite so similar in composition as is commonly 

 assumed to be the case, and further experiments showed that whUe petroleum 

 spirit had but little tendency to combine with bromine, and was only with great 

 difficulty acted on by nitric acid, the shale naphtha presented a marked difference 

 in these respects. These facts of course point to a probability, almost amounting 

 to certainty, that shale naphtha contains a large proportion of olefines or hydro- 

 carbons of the general formula 0„ tl^,, while petroleum spirit consists chiefly of 

 parajlns or hydrocarbons of the formula C„H„„+3. Quantitative experiments 

 vnth nitric acid show that whUe shale naphtha contains only 15 to 25 per cent, 

 of paraffins, the balance being olefines, in petroleum spirit these proportions are 

 reversed. 



The burning oil from shale also consists chiefly of olefines, while in kerosene 

 or petroleum burning oil paraflans predominate. 



The following table shows the general composition of the products from shale 

 and petroleum : — 



