Considering the action taken by the International Conference on Labor Regulation at Berne in 1906 in regard to the night work of women, the question suggests itself whether the treaty-making power might not be used for the purpose of securing national protection of women in industry. The Berne convention provides that the industrial work of women at night shall be prohibited, with a specification of the number of hours, and subject to certain exceptions particularly set forth. Suppose the United States had been a party to this convention, what would have been the effect? Under the federal constitution, the treaties are the highest law of the land, and treaties of the United States sometimes deal with subjects otherwise withdrawn from federal jurisdiction and belonging to the states, so especially with the right of aliens to hold land. But these treaty provisions are directly operative without further legislation. This does not appear to be true of the Berne Convention. For although the convention regarding night-work uses the word “shall be prohibited” (_sera interdit_) while the phosphorus convention says the parties “bind themselves to prohibit” (_s’engagent à interdire_), yet even the night-work convention leaves it to the signatory states to define what shall be regarded as industrial enterprises, and therefore is not operative without further legislation. For the United States the convention would therefore have been ineffective without the concurrent action of each state. Even however if a convention should create immediately operative restraints, they would probably be ineffective in practice without appropriate administrative arrangements, and these, under the constitution, can be provided only by the states. On the whole, the treaty-making power can hardly be relied upon to break down the barriers created by state autonomy. Fortunately, however, the work of agitation and public education knows no state lines, and the national influences which are thus constantly operative cannot fail to produce a certain uniformity of legislation which will increase as the wisdom of restrictive or regulative measures approves itself by their success. In the work of public enlightenment, the federal government can and does bear its share, since the expenditure of national funds is not bound by the same limitations as the enactment of laws intended to bind private action, and since the constitution, through the provision for the census, lends a direct sanction to inquiries into social and economic conditions. For the present, these non-compulsory agencies must be relied upon as the main forces in the work of unification. FOOTNOTES: [46] _Cf. in re_ Bradwell, 55 Ill. 535, Bradwell v. Illinois, 16 Wallace, 130, 1873. [47] _In re_ Maguire, 57 Cal. 604. [48] _Ex parte_ Hayes, 98 Cal. 556. [49] Foster _v._ Police Commissioners, 102 Cal. 483. [50] People _v._ Williams, 189 N. Y. 131. [51] 198 U. S. 45. [52] 208 U. S. 412.