8 BULLETIN 399, U. S. DEPAETMENT OF AGRICULTURE. 



on the contrary, more completely emulsified it. Treatment with 

 kieselguhr (infusorial earth) and subsequent filtering under differ- 

 ence in pressure yielded a clear oil, but the process was entirely too 

 slow in operation. After several experiments the following method 

 was found to work very satisfactorily. 



All the water possible was removed with a separatory funnel, and 

 the emulsion warmed on a water bath to not over 90° C. To this was 

 added one-tenth its volume of a hot solution containing 2 per cent of 

 gelatin and the whole thoroughly mixed. To the warm mixture was 

 added one-fourth its volume of a hot solution containing approxi- 

 mately 10 per cent of tannin. The emulsifying agent was thus brought 

 into a state of coagulation, and the oil was released. The mass was 



Fig. 5.— Experimental still used in extracting orange oil: a, still; 6, condenser; c, receiver; d, separatory 



funnel. 



now thrown into a sack made of heavy Canton flannel and again 

 pressed. The oil and water thus pressed out were separated by means 

 of the separatory funnel, and the oil dried with quicklime and filtered. 

 The filtered oil constitutes the marketable product. 



When the method was thus proved to be practicable, a cheap and 

 abundant supply of tannin was sought. This was found in the 

 rhizome of the common saw palmetto, which contains approx- 

 imately 7.58 per cent of tannin.^ A portion of tliis rhizome was 

 boiled with water in a copper vessel for several hours and the liquor 

 then strained off. Ten pounds of the fresh rhizome was found to 

 yield a supply of tannin solution sufficient to treat the emulsion 

 from at least a ton of oranges. 



1 Trimble, H. The tannins of the palmettos. In Gard. and Forest, v. 9, no. 428, p. 182-183. 1896. 



