which he was doing business on behalf of his master; and a succeeding day on which, for the same offence against commercial integrity, he could be charged before a magistrate and ultimately punished by the law. Thus the difference between scientific progress and social progress is not so great as has been sometimes imagined. And on the other hand, although to the casual observer scientific discoveries and new inventions often appear to have been attained at a single step, to a person interested in the particular branch of science, or the particular path of invention where a new achievement occurs, it is generally quite evident that the latter has been led up to by steady progress extending over a long period. The existence of unidentified constituents in atmospheric air, for instance, must have been long suspected before the isolation of argon gave, to the public eye, the impression of a sudden discovery: and astronomical disturbances have generally puzzled a great army of observers for a long time before the public is indulged by the announcement of a "new" star in the heavens. To the reader who has been good enough to grant any validity at all to the arguments by which I have sought to show that, as time goes on, there will be a decreasing tendency to attempt desired reforms by legislative process, and an increasing tendency to make the public the guardian of its own security, it will be evident that any differences which exist between the nature of scientific progress and the nature of social progress are likely to be accentuated rather than diminished in the course of this century. A change brought about by the spontaneous activity of the people naturally occurs without the definite line of demarcation created by an Act of Parliament.