MABERY. — SULPHUR PETROLEUMS. 65 



products may be formed without the aid of high temperatures is not so easily 

 demonstrated. That any considerable elevation in temperature has accompanied 

 the formation of petroleum, at^ least in the limestones, is rendered extremely 

 improbable by tiie condition of the oil rock. Sections of the Corniferous lime- 

 stone from wells drilled at Petrolia exhibit very plainly the conditions of strati- 

 fication, without the slightest indication of metamorphic action. The rock 

 consists of alternate light and dark layers, the light portion being much more 

 compact than the darker strata, which are more granular, and offer greater 

 resistance to the drill. As our analyses show, the two varieties of rock do not 

 differ essentially in their composition. The darker portions of the strata evi- 

 dently contain more oil. 



Concerning the question as to whether petroleums can be sharply divided as 

 to their origin, the limestone oils having their source in the decomposition of 

 organic matter of animal origin, and other petroleums in the decomposition of 

 vegetable matter, more experimental evidence is necessary. 



The absence of nitrogenous organic bodies in petroleum has been suggested, 

 by the adherents of vegetable matter as the source, as a serious objection to 

 its origin in the decomposition of animal bodies. It is true that in other oils 

 than those found in the limestones the quantities of nitrogen hitherto found are 

 extremely small, as already explained (page 16). As further evidence of the 

 minute proportion of nitrogen in non-sulphur oils, we have determined this ele- 

 ment in Chinese petroleum (1), in a colorless Italian petroleum (2), in Macks- 

 burg, Ohio, oil, 1,900 foot level (3), and in a peculiar light yellow Berea Grit oil, 

 500 foot level (4), from Archer's Fork, Ohio, that is at present refined in large 

 quantities. The last named oil deposits parafline when cooled to 10°. 



Determinations by the Kjeldahl method gave the following results : — 



Trenton Limestone Oil. Corniferous Limestone Oils. 



(1) 0.10 (1) 0.26 (1) 0.16 



(2) 0.014 (2) 0.23 (2) 0.18 



(3) 0.035 (3) 0.21 (3) 0.21 



(4) 0.023 



It is therefore evident that in general a higher percentage of nitrogen is a 

 distinctive quality of the limestone petroleums. 



As mentioned above, we now have in hand certain nitrogenous bodies 

 extracted from Ohio petroleum which resemble derivatives of the pyridine 

 bases. In our earlier work on the sulphur compounds in the limestone oils 

 (These Proceedings, XXV. 228), there were indications that these petroleums 

 contain certain ethereal oils of vegetable origin beside other oils resembling 

 the terpenes. A question may therefore arise as to whether the limestone oils 

 have been derived exclusively from organic matter of animal origin. 



VOL. XXXI. (n. S. XXIII.) 5 



