This law states that, “When two different elements separately combine with a fixed mass of a third element, then the proportions in which they combine with one another shall either be same or some multiple of It.
Explanation with Example:
Carbon C and oxygen 0 separately combine with Hydrogen H to form methane CH4 and water h2O respectively.
The law says that if carbon C and oxygen 0 combines with each other, they with doing so In the same ratio or multiple ratios.
If carbon and oxygen combine to form C02 then the ratio of C and O2 is 12: 32 or 3: 8 which is the same as in CH4.