118 Dr. A. W. Hofman on the Organic Bases 



surface of the acid solution. I drew off the acid liquor with 

 a siphon, and again agitated it with a fresh supply of oil. In 

 a short time I obtained a tolerably concentrated solution of 

 the basic compounds in hydrochloric acid. In order to sepa- 

 rate these bases I mingled the liquid, — previously filtered 

 through linen and gray bibulous paper, — with an excess of 

 milk of lime, in a large copper retort with a well-adapted con- 

 denser, and distilled over a strong fire. When properly 

 mixed the mass becomes very hot, and a large quantity of suf- 

 focating vapours are eliminated ; therefore the still-head must 

 be speedily affixed to prevent loss. 



At the commencement of this process an opake liquid di- 

 stilled over, upon which floated drops of a blackish-brown oil 

 of a similar smell to that which was noticed at the filling of 

 the alembic. This liquid became clear when treated with hy- 

 drochloric acid, and yielded after concentration, when mixed 

 with caustic potash, oily globules, possessing the above-men- 

 tioned stifling odour. 



In the course of the operation this peculiar smell diminished 

 greatly, and when about half of the liquid, which was in the 

 retort, had passed over, the odour changed completely and 

 was succeeded by one not disagreeable, in some respects re- 

 sembling oil of bitter almonds. At this stage of the process, the 

 aqueous solution, although turbid, contained only traces of 

 dissolved oil. I therefore changed the receiver, finding that 

 the oil now coming over differed from the former. 



The basic fluids obtained in this manner still contained a 

 certain quantity of foreign oil, which must have mechanically 

 passed through the filters with the hydrochloric solution, and 

 distilled over with the bases. Of their presence I readily con- 

 vinced myself by dissolving the bases in hydrochloric or sul- 

 phuric acid. There remained small quantities of extraneous 

 oils, even when the bases were repeatedly separated and dis- 

 solved in acids. I succeeded in separating these foreign oils 

 by dissolving in aether and adding a dilute solution either of 

 sulphuric or hydrochloric acids. In this case the bases com- 

 bined with the acid, while the non-basic oils remained dis- 

 solved in the aather. 



The acid solution ot the bases was carefully separated from 

 the aethereal solution of oil, and decomposed with hydrate of 

 potash. Carbonates of potash and soda, which will also 

 answer the purpose, must not be employed, because the car- 

 bonic acid generated is apt to carry off quantities of oily va- 

 pour. The decomposition succeeds best when performed in a 

 long narrow glass cylinder, the oil rises as a perfect homoge- 

 neous stratum to the surface of the menstruum, where it can be 



