The law of multiple proportions asserts that if two elements form more than' one compound, then the weights of the one element Law of which are found combined with unit weight of the other multiple in the different compounds, must be in the ratio of two propor or more whole numbers.

Law of If we know the weights a and b of two elements that are reciprocal found in union with unit weight of a third element, then proporwe can predict the composition of the compounds which the first two elements can form with each other; either the weights a and b will combine exactly, or if not, these weights must be multiplied by integers to obtain the composition of a compound.

From their work it follows that the ratio of the weights of oxygen combined with unit weight of carbon in the two oxides is 1.99995, or with somewhat different data, 1.9996.