OIL FROM THE SEEDS OF BURSARIA SPINOSA. 401 



bath and the soap dissolved in water and filtered. The 

 filtrate was then acidified with dilute sulphuric acid in 

 order to liberate the fatty acids. The free acids which 

 were liquid were separated from the aqueous solution and 

 the latter shaken with ether. The ether was separated 

 from the aqueous solution, dried, and the solvent removed 

 by evaporation. The residue was added to the free fatty 

 acids and the whole dissolved in ether. The ethereal 

 solution of the free acids was then washed with distilled 

 water until the washings were neutral to litmus. The 

 ethereal solution was then dried over calcium chloride and 

 the ether removed by evaporation. The free fatty acids 

 were fluid at ordinary temperatures and no separation of 

 solid matter took place on allowing the acids to stand for 

 a couple of days. 



Separation of the fatty acids.— The free fatty acids were 

 converted into their lead salts by heating at a low temper- 

 ature on a water-bath with excess of lead carbonate. The 

 lead salts were then mixed with ether in a stoppered flask 

 and the whole allowed to stand with frequent shakings for 

 several days. The greater part of the lead salts dissolved. 

 The solution was decanted and the residue washed with 

 ether. The ethereal solution was then shaken with 

 successive small quantities of dilute hydrochloric acid until 

 all the lead salts were decomposed. The ethereal solution 

 was washed, dried over calcium chloride and the ether 

 removed by evaporation. The residual free fatty acid was 

 light yellow in colour. It formed an elaidin and readily 

 absorbed iodine. A combustion of the oil gave results very 

 near to those required for oleic acid 



(1) C 75'46f°; H ll*67f 



(2) 75'4f; H n*87°/° 



but the carbon is too low. On allowing this acid to stand 

 in a stoppered bottle for two days at about 20° 0. a very 

 small quantity of solid matter separated. This was removed 



