PRODUCTION AND UTILIZATION OF FATS AND OILS 25 
Uses / 
Tung oil has a strong laxative action, which makes it unfit for 
edible purposes. Being a drying oil, it is used chiefly in making 
varnishes, enamels, and floor and wall paints. In China it is also 
employed for waterproofing paper and fabrics. The so-called spar 
varnishes, which are not discolored when wet, consist largely of tung 
oil and rosin glyceride (ester gum) . 
The press cake, being unfit for cattle food, is used as a fertilizer 
or for fuel. 
CANDLENUT OR LUMBANG OIL 
Candlenut oil is obtained from the kernels of the nuts of a large 
tree (Aleurites iiwluccama) growing in the Philippines, Polynesia, 
the Malayan region, the Hawaiian Islands, and other tropical coun- 
tries. These kernels contain from 50 to more than 60 per cent of oil. 
The Hawaiian^ formerly strung the nuts on slender bamboos and 
used them for lighting their huts. This gave rise to the name u can- 
dlenut." Some candlenut oil is imported from the Philippines into 
the United States. 
The nuts have very hard shells which are difficult to crack. It is 
difficult also to separate the kernels from the shells. The procedure 
which yields the better grades of oil is to crack the dried nuts by 
hand and pick out the kernels with a pointed instrument, a slow and 
tedious operation. The kernels are crushed and pressed hot, for the 
most part in primitive mills. Cold pressing yields a much lighter- 
colored oil. 
In some localities large quantities of the nuts are collected in shal- 
low pits and covered with straw, which is set on fire. The hot nuts 
are sprinkled with cold water, thus causing the shells to crack. In 
other places the nuts are boiled for several hours with water, which 
effects the separation of the kernels from the shells, and then cracked 
by hand. During this treatment the color of the kernels changes from 
white to brown, so that only a dark oil can be obtained from them. 
In the Philippines the oil is used for the manufacture of paint, 
varnish, and soap. Candlenut oil, unlike tung oil, does not solidify 
when heated to 482° F. Extensive experiments in the Philippines 
have indicated that the oil can be used for any purpose for which 
linseed oil is now employed. As the press cake is poisonous, its only 
use is as a fertilizer. 
PERILLA OIL 
Perilla oil is obtained from the seeds of plants of several species, in- 
cluding PeHlla nankinensis and ocymoides L., which grow in China, 
Japan, Manchuria, and eastern and northern India. The commercial 
oil seems to be obtained chiefly from P. ocymoides, the seeds of which 
are about as large as mustard seeds and average 35 per cent in oil. 
It is reported that a yield of 20 bushels of seed per acre is obtained in 
Japan. The variety P. nankinensis appears to have been employed 
in all the experiments on the culture of perilla conducted in the 
United States. As perilla seeds have not been produced in commer- 
cial quantities in the United States, all the perilla oil used here is 
imported from the Orient. 
