Carbon and oxygen combine to form carbon monoxide and carbon dioxide explains the law

Law of conservation of mass was proposed by 

Copper forms cupric oxide and cuprous oxide with oxygen. This explains

Law of multiple proportions is illustrated by

The quantitative aspects of chemical changes are governed by certain laws called

Water obtained by different sources has the ratio of weight of oxygen to hydrogen a constant. This explains

The weight of one element that seperately combines with a fixed weight of another element bear a simple integral ratios. This law is

The sum of masses of substances before and after a chemical reaction remains constant. This law is 

In the formation of carbon monoxide and carbon dioxide, the weights of oxygen that combine with carbon in the ratio

Two different oxides of a metal contain 20% and 27% oxygen by weight. This is in accordance with