210 



steam distilled without separating the alkali. The distilla- 

 tion took about two and a half hours; — 



Specific Refractive Disper- 

 Amount. Rotation. Gravity. Index. sion. 



(a) 28 CCS. -5-21° 0-9004 1-4669 0-01009 



(b) 815 CCS. -5-19° 0-9059 1*4679 0*01011 



(c) 50 CCS. -5-64° 0-9257 1-4759 0-01037 



A 6. — One litre of crude oil, stored in the dark since dis- 

 tillation, was shaken with 600 ccs. of a 16 per cent, sodium 

 hydroxide solution and steam distilled in the presence of the 

 alkali. The rotation of the oil was — 7'28°. The distillate 

 was collected in two fractions : — 



Amount. Rotation. Specific gravit5^ 



(a) 750 CCS. -4-84° 0-9065 



(b) 150 CCS. -4-8° 0-9144 



B. Estimation of Cineol in Crude Oil. 



It was found that the resorcinol method of estimating 

 cineol gave very erroneous results with this oil. The aldehyde 

 and other bodies present were, to a large extent, extracted by 

 the resorcinol solution, thus giving results which were far too 

 high. In one test, the oil which was not absorbed by the 

 resorcinol solution had the same rotation as the crude oil 

 itself, indicating that the resorcinol absorbed other bodies 

 besides cineol. This is confirmed by the appreciable rota- 

 tion (often as high as — 2) of the cineol separated from the 

 cineol resorcinol compound. 



Phosphoric Acid Method. — In connection with the estim- 

 ation of cineol by the phosphoric acid method, the writer 

 carried out estimations on control samples, containing various 

 proportions of pure cineol diluted with ordinary commercial 

 turpentine. 



Those samples containing about 70 per cent, cineol (by 

 volume) gave excellent results, while 80 per cent, cineol 

 samples were slightly low, and 60 per cent, cineol and less 

 gave very erroneous results, a 60 per cent, sample only aver- 

 aging 45 per cent, cineol and a 50 per cent, one appeared to 

 contain 30 per cent, cineol. It was observed that accurate 

 results were only obtained when the cineol phosphate mass 

 (before pressing) was of a powdery nature, a pasty mass of 

 cineol phosphate invariably giving low results. A probable 

 explanation of these low results is that the pasty condition is 

 caused by the solvent action of the other constituents on the 

 cineol phosphate compound. Tlie addition compound so dis- 

 • solved being removed on pressing the solid cake thus causes 

 a low result. A pasty compound of cineol phosphate resulted 



