44: PROCEEDINGS OF THE AMERICAN ACADEMY. 



oil was undertaken by Pelouze and Caliours * for the purpose of sepa- 

 rating and identifying the hydrocarbons therein contained. Their 

 attention was confined to the series C„H2„ + 2, and published accounts 

 of their woik contain no allusion to any otiier constituents than this 

 series of hydrocarbons. They failed to observe the jiresence of aro- 

 matic hydrocarbons, although, as already mentioned, Schorlemmer 

 discovered the presence of the benzol hydrocarbons in " real Cana- 

 dian rock oil, a thick black liquid of a very unpleasant odor." 



My attention was first attracted to Canadian petroleum in 1890, 

 when I procured some of the crude oil and also a quantity of the 

 "sludge" from the refining of burning oil, for the purpose of examin- 

 ing the sulphur compounds. The peculiar features of the distillates in 

 a preliminary examination f invited further attention, and I determined 

 to undertake, with the aid of the refiners, as complete an examination 

 as was possible with the appliances at my command. It may seem 

 somewhat surprising that such an examination of the sulphur petro- 

 leums in general has not previously been undertaken ; but it should 

 be borne in mind that it requires the facilities of a well equipped 

 organic and technological laboratory for the manipulation of con- 

 siderable quantities of material, and a corps of efficient chemists with 

 aid from the refinery of crude oils, partially refined products, and resi- 

 dues. Even with all necessary accessories, aside fi-om the tedious 

 routine labor, there are certain features of decomposition and slow 

 separation of constituents that render this work extremely difficult. 

 In view of possible changes in the composition of petroleum, in the 

 course of time, as wells become exhausted or the oil is taken from 

 different depths, or indeed with the possibility of future exhaustion of 

 oil fields which at present appear to be in the zenith of their produc- 

 tion", it would seem that a comprehensive study of these oils should not 

 be too long delayed. 



From the peculiar nature of petroleum and its numerous constitu- 

 ents, all of which, so far as they have been examined aside from the 

 lighter hydrocarbons of the series C„H2„ + o, or the series C„H2n5 are 

 present in small quantities, any attempt toward a separation of these 

 constituents involves the manipulation of large volumes of the oils in 

 such a manner as to prevent so far as possible decompositions, which 

 cannot be entirely avoided even with the greatest care. On this 

 account satisfactory results can be hoped for only in products that have 



* Bull. Soc. Chim., 1863, p. 228. 

 t Amer. Cliem. Journ., 1894, p. 89. 



