Province of Santa Clara, Cuba. 



445 



at higher temperatures contain increasing percentages of naph- 

 thenes, approximately equal amounts being finally found. 



It has already been mentioned that with the naphtha, a sub- 

 stance was obtained which was described by the driller as 

 paraffin. It was a grey substance, somewhat gelatinous, and 

 similar in appearance to an oil emulsion. Its composition was 

 found to be : 



Oil 81$ 



Water _ ._. 14$ 



Clay .._ _ 5f 



in the form of an emulsion. 

 The oil had a 



Sp. gr. Westphal 15-6° 0-738 



N D 25° 1-4100 



Distillation JEngler. 



Temperature % 15° Sp. gr. 20°/20° N D 25° 



-75° 0-4 1-4045 



75°-100° 18-0 0-72 0-7217 1*4006 



100°-125° 56*4 0-74 0*7372 1-4090 



125°-150° 18*4 0-75 0*7500 1*4161 



Residue 3*4 1-4499 



This oil is practically identical with the clear naphtha, except 

 for a slightly higher gravity. It was more deeply colored and 

 had a larger amount of brown sediment. 



Action with reagents. Oil from emulsion. Removed by 



Soda -<dfo 



Concentrated acid 1*5$ 



Fuming acid 0*0$ 



The water had 2*31 per cent total solids. 



The clay, which was gray, lost 15*7 per cent on ignition, 

 the iron being oxidized. It was submitted to the Office of 

 Public Roads, Washington, D. C, and an examination by Dr. 

 Lord showed that the indurated material consisted essentially 

 of highly decomposed fragments of a ferruginous rhyolitic 

 glass and rounded grains of bitumen cemented together by 

 chalcedonic silica and an indefinite hydrated silicate. The clay 

 is composed of the secondary products resulting from the 

 decomposition of the rhyolite, with some bitumen grains and 

 fragments of undecomposed glass. 



The emulsion is of the greatest interest. 



Gilpin and Cram have shown* that when petroleum is allowed 

 to rise in a tube packed with fuller's earth, a fractionation 



* Am. Chem. J., xl, 495. This property was first pointed out by Day, 

 Proc. Am. Philos. Soc, xxxvi, 154. 



