petroleum ether—Redistilled petroleum ether, boiling under 75° C., shall be used.
Then add about 60 cubic centimeters of ether, petroleum ether or 86 degs.
The acid is then neutralized and the paraffine extracted by petroleum ether.
Draw off the petroleum ether layer as closely as possible by means of a slender glass siphon into a separatory funnel of 500 cc.
The ointment will require extraction of the fat by petroleum ether; this accomplished, the determination of its strength is easy.
On evaporation of the petroleum ether, the nitro-benzene is left, perhaps mixed with fatty matters.
petroleum ether, on the other hand, only slightly dissolves it in the cold, more on warming.
petroleum ether dissolves it by the aid of heat, but the alkaloid separates in crystals on cooling.
Chloroform dissolves thebaine with difficulty out of both acid and alkaline solutions; petroleum ether extracts it from neither.
Quebrachine may be extracted from an acid solution by chloroform, but not by petroleum ether.