PRODUCTION AND CONSERVATION OF FATS AND OILS. 45 
experts who advocated the planting of oil-producing crops during the 
years of preparation for the war, such a situation probably would 
have been avoided. For vegetable oils are being used in ever-increas- 
ing amounts to supplement the animal fats and oils. Some, like cot- 
tonseed oil, make a satisfactory substitute for part at least of the 
animal fats in such products as lard, while some of the less well-known 
vegetable oils, like peanut and corn, are rapidly growing in public 
favor as substitutes for olive oil, which has recently been very dim- 
cult to obtain. It has also been found possible to conserve our supply 
of linseed oil by using tung and similar oils in making paint, varnishes, 
and other technical products. It is believed that the manufacturer 
of vegetable oils may practice many more economies than he now 
does, thus eliminating certain sources of waste. 
The recently devised hydrogenation process has made it possible 
to secure a very satisfactory lard compound, in which a vegetable oil 
replaces all of the often more expensive animal fat. By means of this 
same process, various fish oils now employed only for technical purposes 
may be rendered edible. 
Conservation in food materials is still essential. To this end the 
small butcher and farmer are urged to trim the animals they slaughter 
closely to obtain all the fat possible for rendering as lard or tallow. 
The housewife, too, should be as economical as possible in her use of 
animal fats. 
The question of recovering fatty matter from garbage and trade 
wastes is receiving much attention at this time, and it is probable 
that effective methods for doing this will soon be worked out. 
