21 



But in no case can the above method be considered as a com- 

 plete separation. In alcoholic solutions each fraction assumed 

 a green or greenish black color with alkalies, the color varying 

 with the concentration of the solution and the strength of the 

 alkali used. 



SEPARATION OF THE LACRESINS BY SOLVENTS. 

 SOLUBILITY OF THE ORIGINAL ALCOHOLIC RESIDUE. 



On first trial it appeared as though the alcoholic residue 

 might be soluble in any of the ordinary solvents for oils and 

 resins, but investigation proved that it was not completely soluble 

 in carbon disulphide, methyl alcohol, amyl alcohol or petroleum 

 benzin in all proportions. 



After numerous experiments the following method of pro- 

 cedure was adopted. The alcoholic residue was dissolved in the 

 proportion of i part to 7 of petroleum benzin, boiling point not 

 over 60 C., forming a clear solution, but further addition of ben- 

 zin caused a precipitate. This was then poured into 55 parts of 

 benzin which produced the immediate separation of a thick brown 

 mass from which the still cloudy benzin was decanted. 

 The brown deposit was dissolved in a small quantity of benzin and 

 again separated by adding a larger amount. After this operation 

 was repeated several times the deposit became entirely insoluble 

 in benzin. It was then washed with benzin until the last washings 

 were colorless. The washings were added* to the portions pre- 

 viously decanted and allowed to stand 12 hours when the ben- 

 zin became clear and was not affected by the further addition of 

 benzin. The second deposit was dissolved, again precipitated by 

 benzin and washed by agitation with benzin. The second deposit 

 was thinner and lighter in color than the first. 



By this method the alcoholic residue was separated into two 

 distinct substances, a benzin-soluble, and a benzin-insoluble. 

 The first and second deposit from benzin, while differing some- 

 what in physical appearance could not be said to consist of two 

 distinct substances but doubtless consisted of mixtures of the 

 same substances in varying proportions. Each was mixed with 

 a small quantity of ether and added to methyl alcohol which im- 

 mediately became cloudy and on standing a short time formed a 

 deposit. The solution remained clear on the further addition of 

 methyl alcohol. The residue was separated and washed with 



