Dalton's atomic theory could not explain law of ____?

Dalton's atomic theory proposed that all mater are composed of atom that are indivisible and indestructible. Atoms of one element are single while different elements have different atoms that have different sizes and masses.

Dalton theory could explain the laws of chemical combination. However, it could not explain the law of gaseous volumes. The law of gaseous volumes can only be explained with the help of ideal gas equation and mole-mole analysis.