FUEL 297 
for market. The oils of wintergreen (Fig. 147), marjoram 
(Fig. 137), coriander (Fig. 143), thyme (Fig. 134), caraway 
(Fig. 140), and many others are thus used to a greater or less 
extent. 
These same volatile oils enter also into the manufacture 
of perfumery; and for this purpose many other volatile oils 
are more or less in demand, as, for example, the oils of nutmeg 
(Fig. 129), allspice (Fig. 123), sassafras (Fig. 160), peppermint 
(Fig. 146), spearmint (Fig. 135), orange-peel and orange- 
flowers (Fig. 106), and the oil distilled from the wood of red 
cedar (Fig. 261). It is to the fragrant oil obtained from the 
bark of white birch (Fig. 254) that the characteristic odor of 
Russia leather is due. 
None but fixed oils can serve as lubricants; and of these, 
only the non-drying ones are suitable. The vegetable lubri- 
cants most extensively employed are (1) olive-oil, used for 
this purpose mostly in southern European countries where a 
sufficiently good quality may be obtained at a low price, 
(2) rape-oil from the seed of a variety of turnip grown widely 
in northern Europe and India, and (3) cotton-seed oil used 
largely in this country. 
As illuminants vegetable oils have not to-day the impor- 
tance they had before the introduction of petroleum lamp-oil 
and paraffin candles. Nevertheless, large quantities of 
vegetable illuminants are still consumed, especially in regions 
where mineral or animal oils are comparatively expensive. 
Almost all the fixed oils in common use for other purposes 
have served for burning, but the non-drying oils are pref- 
erable. Olive, peanut, and rape oils, which are all rich in 
olein, are among the best. Palmatin, as we have seen, is an 
important constituent of coconut-oil. This substance sepa- 
rated from the more fluid parts of the coconut-oil and other 
palm-oils affords an excellent material for candles. 
80. Fuel, whether as a source of heat or of power, being 
indispensable to the carrying on of almost every industry, 
and being also a necessity for steam-transportation, for the 
heating of buildings, and for cooking, it is plain that civiliza- 
tion could not have developed as it has, nor could it possibly 
go on, without this source of heat. 
