60 



" has assumed a very dark color. After being allowed 

 " to stand for twelve hours, it is transferred to a copper 

 " boiler, in the bottom of which are holes, through 

 " which steam is admitted, and passing in a finely 

 " divided state through the oil, raises it to the tempe- 

 " rature of 212°. This steam process is carried on for 

 " six or seven hours ; the oil is then transferred to a 

 " cooler, having the shape of an inverted cone, termi- 

 " nating in a short pipe, provided with a stop- cock 

 " inserted in its side, a little distance from the bottom. 

 " After being allowed to stand till the liquids are 

 " separated, which generally takes about twelve hours, 

 " the acid liquor is drawn off through the pipe at the 

 " bottom, and the clear oil by the stop-cock in the side 

 " of the cooler : all below this tap is generally turbid, 

 f ' and is clarified by subsidence, or mixed with the next 

 " portion of oil." 



Refining is also effected by agitating with a satu- 

 rated solution of caustic soda. After a time a sapona- 

 ceous deposit is precipitated, and the remainder becomes 

 quite clear and pure. 



But while explaining a few of the more elaborate 

 methods used for refining Olive oil, I invite those of my 

 readers who contemplate the cultivation of the Olive in 

 Queensland, to be content with keeping in view for 

 their first manufacture, purification by simple settle- 

 ment; because, however effectual any of these other 

 processes may be, this method is found sufficient for a 

 vast quantity of the best Olive oil produced in the 

 world. 



