a reasonable relation to the protection of the
buyers and the preservation in transit of the fruit.[302] Similarly, an
ordinance fixing standard sizes of bread loaves and prohibiting the sale
of other sizes is not unconstitutional.[303] However, by a case decided
in 1924, a "tolerance" of only two ounces in excess of the minimum
weight of a loaf of bread is unreasonable when it is impossible to
manufacture good bread without frequently exceeding the prescribed
tolerance and is consequently unconstitutional;[304] but by one decided
ten years later, regulations issued in furtherance of a statutory
authorization which impose a rate of tolerance not to exceed three
ounces to a pound of bread and requiring that the bread maintain the
statutory minimum weight for not less than 12 hours after cooling are
constitutional.[305] Likewise a law requiring that lard not sold in bulk
should be put upon in containers holding one, three, or five pounds
weight, or some whole multiple of these numbers, does not deprive
sellers of their property without the process of law.[306]

The right of a manufacturer to maintain secrecy as to his compounds and
processes must be held subject to the right of the State, in the
exercise of the police power and in the promotion of fair dealing, to
require that the nature of the product be fairly set forth.[307] Nor
does a statute providing that the purchaser of harvesting or threshing
machinery for his own use shall have a reasonable time after delivery
for inspecting and testing it, and permitting recission of the contract
if the machinery does not prove reasonably adequate, and further
declaring any agreement contrary to its provisions to be against public
policy and void, does not violate the due process clause.[308]

Blue Sky Laws; Laws Regulating Boards of Trade, Etc.--In the
exercise of its power to prevent fraud and imposition, a State may
regulate trading in securities within its borders, require a license of
those engaging in such dealing, make issuance of a license dependent on
a public officer's being satisfied of the good repute of the applicants,
and permit him, subject to judicial review of his findings, to revoke
the same.[309] A State may forbid the giving of options to sell or buy
at a future time any grain or other commodity.[310] It may also forbid
sales on margin for future delivery;[311] and may prohibit the keeping
of places where stocks, grain, etc., are sold but not paid for at th