Soc., 1890, 47, p. 364), who found that a film of olive oil spread over the surface of water produced a perceptible effect on small floating pieces of camphor, at places at which the thickness of the film was io 6 X10 -8 cms., but produced no perceptible effect at all at places where the thickness of the film was 8.1 X10 -8 cms. Thus a certain phenomenon, of the nature of capillary action, is seen to depend for its existence on the linear dimensions of the film of oil; the physical properties of a film of thickness Io 6Xio 8 cms. are found to be in some way qualitatively different from those of a film of thickness 8.1 X io 8 cms. Here is proof that the film of oil is not a continuous homogeneous structure, and we are led to suspect that the scale on which the structure is formed has a unit of length comparable with 8 X10 -8 cms. The probability of this conjecture is strengthened when it is discovered that in all phenomena of this type the critical length connected with the stage at which the phenomenon changes its nature is of the order of magnitude of 10 -8 cms.
The following results have been obtained Clean 74.o Greasy to the point where camphor motions nearly cease 53.o Saturated with olive oil 41.0 Saturated with sodium oleate 25 o (Phil.
They differ from liturgical lights in that, whereas these must be tapers of pure beeswax or lamps fed with pure olive oil (except by special dispensation under certain circumstances), those used merely to add splendour to the celebration may be of any material; the only exception being, that in the decoration of the altar gas-lights are forbidden.
To prepare it olive oil is saponified with potash, and lead acetate added; the lead salts are separated, dried, and extracted with ether, which dissolves the lead oleate; the solution is then treated with hydrochloric acid, the lead chloride filtered off, the liquid concentrated, and finally distilled under diminished pressure.
Next in importance is margarine, the British production of which does not suffice for the consumption, so that large quantities must be imported from Holland, edible olive oil from Italy, the south of France, Spain and the Mediterranean ports generally.
Two preparations of hard soap (sodium oleate), made by acting on olive oil with caustic soda, are used in medicine: (1) Emplastrum saponis, made with lead plaster; (2) Pilula saponis cornposita, which contains one in five parts of opium.
There is a general tendency to obesity, which is much admired by the Moors in their women, young girls being stuffed like chickens, with paste-balls mixed with honey, or with spoonfuls of olive oil and sesame, to give them the necessary corpulence.
The olive oil produced is mainly mixed with that from Genoa or Provence, and placed on the market under the name of the latter.
While this is being obtained, magnesia, castor oil or olive oil can be given; or failing all these, copious draughts of water.
In Germany tallow is the principal fat; in France olive oil occupies the chief place and the product is known as Marseilles or Castile soap; and in England tallow and palm oil are largely used.