32 PROCEEDINGS OF THE AMERICAN ACADEMY. 



presence in the Pennsylvania oil of the hexahydro series. The series 

 with less hydrogen seems to be removed only very slowly, even by 

 vigorous treatment with a mixture of nitric and sulphuric acids. 



In continuing the separations above 120°, after the eleventh distilla- 

 tion the oils collected iu considerable quantities within the limits of one 

 degree : — 



120^-121^ 121^-122' 122^-123° 123^-124^ 124°-125^ 125^-126' 126^-127^ 127°-128=' 



Grams 35 40 80 70 75 75 60 40 



Notwithstanding our endeavors to separate the fraction 122°-125° 

 into higher and lower constituents, they may still be mixtures; aro- 

 matic derivatives are here present in small quantity. If in more pro- 

 longed separations distillates still persist within the same limits, they 

 will be submitted to careful study in their behavior toward chemical 

 reagents. 



The greater portion of the fraction 125°-lo0° was unfortunately 

 lost by an accident after the eleventh distilUition. Sufficient however 

 was collected at 127°-128° for a vapor density determination; it 

 gave, by the method of Dumas, the value required for the formula 

 CgHjg ; found 3.90, required 3.94. To the liquid collected by War- 

 ren at this point was assigned the boiling point 127°. 6; the vapor 

 density found by him was 3.99, and those observations seem to be 

 confirmed by our results with the Ohio product. The portions dis- 

 tilling between 115° and 130° evidently need to be carefully examined 

 in larger quantities with particular reference to the octanes. The 

 distillates collected between 130°-145° will be considered in connec- 

 tion with the aromatic compounds. 



Between 144° and 148°, after many distillations, the fractions 

 were small in quantity. At the end of the sixth distillation, 65 grams 

 collected at 149°-15l°, of which 40 grams distilled constant at 149°- 

 150°, bar. 756 mm. After prolonged heating with concentrated nitric 

 acid a nitro-compound was formed that remained chiefly in solution in 

 the oil. Upon dilution of the acid an oily liquid separated in small 

 quantities. But when the oil was shaken with sodic hydrate, it 

 became intensely red in color, and by repeated washing with the alka- 

 line solution the nitro-product was in part removed, and it separated 

 again as an oil by acidifying the solution. After washing, the remain- 

 ing oil w.TS dried and heated to boiling during several hours with 

 sodium. It was then distilled from the large quantity of solid that 

 had separated, and the greenish yellow distillate again boiled with 

 sodium. Still more solid separated, and after distillation the oil was 



