een found possible (so far as I am aware) to
alter the proportions in which cotton lint and cotton-seed are yielded
by the cotton plant. Roughly speaking, you get about 2 pounds of
cotton-seed for every 1 pound of cotton lint (or raw cotton), and
though this proportion may vary somewhat from plantation to
plantation, it is upon the knees of the gods, and not upon the will of
the planter that the variation depends. We cannot, therefore, speak
with accuracy of the separate marginal costs of raw cotton and
cotton-seed. It is true that some plantations are so far distant from
any seed-crushing mill that it is not worth while to sell the seed as
a commercial product; and it might seem, therefore, as though we might
regard the entire costs of cotton growing on _such_ plantations as
constituting the marginal costs of raw cotton. But planters, so
situated, derive a considerable value from their cotton-seed by using
it as fodder for their live stock or as a manure. You can, of course,
argue that proper allowance is automatically made for this factor, as
a deduction from the costs of raw cotton, when you add up the expenses
of the plantation. In the same way you can deduct the price which a
planter who sells his cotton-seed obtains for it, from the total costs
of the plantation, and call the remainder the costs of the raw
cotton. But this is really to reason in a circle. For in either case
the magnitude of the deduction depends on the marginal utility of the
cotton-seed. And the notion of the cost of anything becomes blurred
and blunted if we so use it that it must be deduced from the utility
of something else, which is not an agent in the production of the
thing in question.

This point is not merely an academic one. It means that we cannot
explain the _relative_ prices of cotton lint and cotton-seed in terms
of cost at all, whether marginal or otherwise. The influence of cost
will be confined to the _sum_ of the prices of the two things. Upon
this sum it will exert precisely the same influence as it exerts upon
price in general, by affecting the total quantities of the two things
that will be supplied. But upon the distribution of this sum between
lint and seed, cost will exert no influence whatever, because it
cannot affect the proportions in which they are supplied. It may
assist some readers if I state the matter in more concrete terms. Cost
of production will be one of the factors which will result in the
production of an