PRODUCTION OF SWEET-ORANGE OIL. 
In some preliminary experiments it was noted that when a portion 
of the vacuum-distilled oil was macerated with unpressed peel for 
several hours the loss in the volume of the oil recovered was in some 
instances as high as 10 per cent. Some oil had been absorbed by the 
peel, although the peel employed contained all its original content of 
oil. When pressure was applied to this macerated peel all the original 
oil could be pressed out. A portion of the peel pressed before macera- 
tion yielded about 95 per cent of its original oil content. When, 
however, the press cake was 
distilled with water and the 
oil thus produced used to 
macerate the next lot of peel 
to be pressed, the yield of oil 
obtained was approximately 
the original content of the 
peel. With these facts in 
mind, the following method 
was devised for extracting 
sweet-orange oil by pressure : 
An inexpensive press (fig. 4) was 
employed in the experimental work. 
This press consists of a heavy wooden 
frame, a wooden drum fitted with a 
perforated brass cylinder, and a 
heavy screw for applying pressure. 
About 20 pounds of the finely ground 
peel from the first two-thirds of the 
grating drum was placed in a canvas 
sack made of 10-ounce duck and the 
sack placed in the wooden drum. 
Pressure was then applied by means 
of the heavy screw. Before press- 
ing, the peel was thoroughly mixed 
with approximately one-half its 
weight of water and the whole FlG ' ^-Experimental press used in extracting orange oil. 
heated to not over 90° C. The oil and water pressed out were collected in a large 
container, where the oil came to the top and the water was easily removed. 
The press cake was then thrown into a still (fig. 5, a) and distilled with water. A 
small quantity of oil was thus secured which was added to the next lot of peel and the 
mixture allowed to macerate for a short time. After pressing several lots the 
mixture of oil and water was placed in a separatory funnel (fig. 5, d) and all the water 
possible was removed. 
The oil thus obtained formed a thick emulsion with a portion of 
the water. This emulsincation was brought about by means of a 
gumlike substance which was pressed from the ground peel. The 
mixture thus formed was found to resist all the regular methods for 
breaking emulsions. Centrifuging did not throw out the oil, but, 
