AGRICULTURE WITH CHEMISTRY. 2.29

and practised, the annual consumption of salt, for these purposes only, would at least amount to tons more. So that the whole revenue from salt would amount to fs Should this be a greater sum than Government would choose to exact, they may limit, or do away all the duties now mentioned, excepting the duty of 20s. per ton, as soon as the consumption of Britain for all the different purposes shall, at the duty of 20s. a ton,

amount to the net revenue at present collected.

The tax upon water-borne coals now claims attention. Some remarks have already been made on that subject in page 194, but not so fully as the importance of the

subject merits.

The coasting coal trade of Britain is said to employ vessels, on an average, each of__ tons, navigated

by* seamen, most of whom are apprentices; as such the coal trade is reckoned the principal nur- sery for British seamen. There is no coasting or carry- ing trade in the world, of which the cargoes, or articles carried,

* For the reasons already given, this blank, with those which precede it, are

left to be filled up py the reader.