It may conveniently be extended to similar mixtures of sulphur and selenium or tellurium, of bismuth and sulphur, of copper and cuprous oxide, and of iron and carbon, in fact to all cases in which substances can be made to mix in varying proportions without very marked indication of chemical action.
Of mineral constituents, whether used alone or in mixture with nitrogenous manures, phosphates are much more effective than mixtures of salts of potash, soda and magnesia.
These discoveries of Geoffroy and Scheele formed the basis of Chevreul's researches by which he established the constitution of oils and the true nature of soap. In the article Oils it is pointed out that all fatty oils and fats are mixtures of glycerides, that is, of bodies related to the alcohol glycerin C 3H5(OH)3 i and some fatty acid such as palmitic acid (C 16 H 31 0 2)H.
(iii.) If the vapour of A be readily soluble in liquid B, and the vapour of B sparingly soluble in liquid A, and if the vapour pressure of A be greater than that of B, then the vapour pressures of mixtures of A and B will continually diminish as one passes from 100% A to loo% B.
He emphasized that the practical training should include (1) the qualitative and quantitative analysis of mixtures, (2) the preparation of substances according to established methods, (3) original research - a course which has been generally adopted.