COMMERCIAL PRODUCTION OF THYMOL FROM HORSEMINT. 9 
A sample of 28 pounds of horsemint oil, showing on assay 72 
per cent of total phenols, was worked up by this process and 18 
pounds of pure thymol was manufactured from it, which is equal 
to a commercial yield of 64.3 per cent of thymol from the oil. When 
made by this process a perfectly white crystalline product was 
secured; 15 pounds of thymol made by this process in 1915 was 
sold to the trade at a high price. Should a slightly yellow product 
be secured a second distillation would be required. It has been 
found, however, that with ordinary care a high-grade product will 
result from the first distillation. By this process three residues are 
secured in small quantities, the lower boiling fraction consisting 
largely of cymene, the mother liquor from the last crystallization of 
phenols, and the tarlike residue remaining in the retort after the last 
fraction has been removed. Work is at present under way looking 
to the utilization of these residues. 
In order to provide an inexpensive and practical apparatus for 
the extraction of thymol from the oil on a moderate scale, the follow- 
ing apparatus has been devised: 
(1) A flask 12 inches in diameter and 16 inches high, made of about 30-ounce copper. 
The top is brought to a short neck 3 inches in diameter and reenforced by a brass 
band half an inch wide and one-quarter inch thick, turned edgewise to form a ring 
and brazed to the neck, forming a flange. The seam in the flask must be brazed, 
since the temperature of the boiling oil is above the melting point of solder. 
(2) A column 22 inches long of 3-inch thin-walled brass or copper tubing. The 
lower end is fitted with a brass ring of the same size and in the same manner as the 
neck of the flask and with it forming a flange joint. In the lower end of the column 
is brazed a brass or copper disk, set at an angle of about 30°. The top of the tube is 
covered with a cap, brazed on, and in the center is set a piece of three-fourths inch 
brass tubing, about 1 inch long, forming a neck, into which a cork can be fitted. 
About 4 inches below the top a side tube of 1-inch brass tubing is brazed in a slight 
angle downward. This tube should be about 20 inches long and at the free end 
should have an elbow which just fits into the end of the condenser. 
The condenser is of copper, 4£ inches in diameter and about 20 
inches long, and consists of an outer cylinder with a head at each 
end. Running through from one head to the other are seven quar- 
ter-inch tubes of copper or block tin. A side tube at the bottom 
and one at the top serve for the inlet and outlet of the cooling water, 
which moves from the bottom upward about the flues. To each 
end is soldered a brass collar 2 by 2 inches, which serves as a chamber 
about the ends of the flues. This slips over the enlarged end of the 
delivery tube at the top to form a fairly tight joint, while over the 
bottom collar is placed a funnel-shaped nozzle to collect and deliver 
as one stream the liquids which run down the flues. The entire 
condenser can be made with soldered joints, since the water jacket 
will prevent melting. A complete condenser can be bought from 
dealers in chemical and pharmaceutical apparatus or can be made 
at small expense by any good coppersmith. 
