90. The Federal Government may levy Central Excises in all the States, but those States which now enjoy the benefit of a part or the whole of these revenues raised in their areas should, in lieu of such benefit, receive grants on the basis of the average revenue enjoyed by them from these sources during the last three years. In our opinion, neither this arrangement nor the one referred to in the foregoing paragraph should present any difficulty from the purely financial point of view either to the Union or to the States.