Where, however, the fatty material forms the main product, as in the case of palm kernel oil, or sesame and coco-nut oils from damaged seeds (which would no longer yield proper cattle food), the process of extraction will be preferred, especially when the price of oils is high.
The old French oil of turpentine is the best antidote to use in phosphorus poisoning, delaying the toxic effects; but ordinary oils are not only useless but harmful.
The most important of the animal fats are those of the ox and hog, and of the vegetable oils cotton-seed and coco-nut; it is also to be remembered that resin, although not a fat, is also important in soap-making.
The vegetable oils and fats occur chiefly in the seeds, where they are stored to nourish the embryo, whereas in animals the oils and fats are enclosed mainly in the cellular tissues of the intestines and of the back.
The element also occurs in the animal and vegetable kingdoms. It is present in hair and wool, and in albuminous bodies; and is also a constituent of certain vegetable oils, such as the oils of garlic and mustard.
Formerly the animal oils and fats were obtained by heating the tissues containing the oils or fats over a free fire, when the cell membranes burst and the liquid fat flowed out.
There is a great variety in the grades of oils produced in the state, ranging from the heavy asphaltic oils of the Popo Agie and Lander fields to the high-grade lubricants and superior light products obtained from the wells in the Douglas, Salt Creek and Uinta county fields.
The process of distillation of lubricating oils under reduced atmospheric pressure is now in very general use, especially for obtaining the heavier products.
The aromatic bitters such as chamomile flowers, cascarilla bark, hops, orange peel and others contain in addition small quantities of essential oils which increase their local action.
The value of flavouring herbs, condiments and spices is due in a large measure to the essential oils contained in them.