18 PROCEEDINGS OP THE AMERICAN ACADEMY. 



lation hydric sulphide came oflf in considerable quantities, but after the 

 first fraction very little appeared in the succeeding distillates below the 

 point where decomposition began. 



On account of the viscous character of the Ohio and Canadian petro- 

 leums, and the large proportion of heavy oils, temperatures indicated 

 by the thermometer in the vapor of the distillates should he higher 

 than the corresponding temperatures of the oil. To ascertain this 

 difference, crude Findlay oil was distilled, and the temperatures of the 

 distillates and of the oil were noted with the following results : — 



Thermometer in the Oil. Thermometer in the Vapor. Difference, 



o o o 



167 120 47 



180 140 40 



203 160 43 



221 180 41 



238 200 38 



259 220 39 



282 240 42 



301 260 41 



318 280 38 



341 300 41 



Except in the first reading the average difference in temperature is 

 about 40°. 



Determinations of sulphur in the crude oil and in the distillates 

 obtained from it, showed that considerable sulphur was lost during 

 distillation. In order to obtain definite information concerning the 

 quantity lost, 100 grams of the crude oil were distilled under atmos- 

 pheric pressure, and attached to the receiver were flasks containing 

 a solution of sodic hydrate for the purpose of absorbing any hydric 

 sulphide that escaped. In front of the flask containing hydric sul- 

 phide there was connected another flask, which contained alcohol, with 

 a delivery tube in front to absorb volatile products that might result 

 from decomposition. The oil was fractioned to 300°, collecting be- 

 tween 115° and 250°, and between 250° and 300°, and the hydric 

 sulphide was determined after oxidation with bromine by precipita- 

 tion with baric chloride. The percentage of sulphur in the several 

 fractions was also determined. As usual in distillation of the sulphur 

 petroleums, a slight sublimate of sulphur was observed in the neck of 

 the condenser. Upon diluting the alcohol it became slightly turbid, 

 which indicated probably some volatilization of sulphur constituents. 



