The Wealth of Nations by Part 5 Chapter 2 Page 70

exactly of the same nature with the land-tax of England. It neither rises nor falls with the rent of the land. It neither encourages nor discourages improvement. The tithe in the greater part of those parishes which pay what is called a Modus in lieu of all other tithe is a tax of this kind.

During the Mahometan government of Bengal, instead of the payment in kind of a fifth part of the produce, a modus, and, it is said, a very moderate one, was established in the greater part of the districts or zemindaries of the country. Some of the servants of the East India Company, under pretence of restoring the public revenue to its proper value, have, in some provinces, exchanged this modus for a payment in kind. Under their management this change is likely both to discourage cultivation, and to give new opportunities for abuse