Another important line of modern legislation consists in the subjecting of trades to a license for the purpose of _examination_ (the tax feature has been discussed above). Such laws are constitutional when applied to a trade really relating to the public health, but as we have found above, black-smithing is not such an one; when imposed merely for the purpose of raising revenue, such legislation is undoubtedly constitutional under our written constitutions, but opposed to historic English principles, which insisted for seven centuries of statute-making on the utmost liberty of trade. In a South American republic you have to get a concession before going into almost any business, even maintaining a shoe-shop, or a milk farm, which concession is, of course, often obtained by bribery or withheld for corrupt reasons. It is to be hoped that the citizens of our States will never find themselves in that predicament. Still, certain State constitutions, as that of South Carolina, provide absolutely that all trades may be made subject to a tax, and the tendency--particularly in the South--to raise revenue in this way is increasing by leaps and bounds. Among the trades already subjected to such licensing or taxing, we find doctors, of course, and properly, pharmacists, plumbers, pedlars, horse-shoers, osteopaths, dentists, veterinary surgeons, accountants, bakers, junk dealers, coal dealers, optometrists, architects, barbers, commission merchants, embalmers, and nurses. Of course it is a motive to novel or irregular trades to secure a licensing law from the State, for the slight tax insures them protection. This is the reason that we find common statutes allowing osteopaths, etc., to be licensed. So far as I have observed, there is no such statute as yet in any State applying to Christian Scientists. Police regulation for the _safety_ of the public is found nearly entirely in the laws regulating labor, factories, mines, or machinery, and will be accordingly treated in that connection. Laws protecting the public against fraud, which from earliest times has been a branch of police legislation, have been of late years numerous, principally in connection with the prohibition of dealing in futures or sales on margin, of sales of goods in bulk without due precautions and notice to creditors, of the issue of trading stamps or other device tending to mislead the public. Some States have prohibited department stores, but this legislation has been held unconstitutional, though the early English labor statutes forbidding to any person more than one trade or mystery will by the historical student be borne in mind. Usury laws, of course, are still frequent, but decreasing in number with the increasing modern tendency to allow freedom of contract in this as in other matters, except only to such persons as, for instance, pawn-brokers, who peculiarly require police regulation.