among the sick and among the well is often overlooked.  For example, Landouzy, in the Laennec clinic in Paris, estimated recently that in the patients of this clinic, which deals with general medicine, 15 to 18 per cent of the women and 21 to 28 per cent of the men had syphilis.  It is fair to presume, then, that such a percentage would be rather high for the general run of every-day people.  This accords with the estimates, based on large experience, of such men as Lenoir and Fournier, that 13 to 15 per cent of all adult males in Paris have syphilis.  Erb estimated 12 per cent for Berlin, and other estimates give 12 per cent for London.  Collie’s survey of British working men gives 9.2 per cent in those who, in spite of having passed a general health examination, showed the disease by a blood test.  A large body of figures, covering thirty years, and dating back beyond the time when the most sensitive tests of the disease came into use, gives about 8 per cent of more than a million patients in the United States Public Health and Marine Hospital Service as having syphilis.  It should be recalled that this includes essentially active rather than quiescent cases, and is therefore probably too low.

+Current Estimates of the Prevalence of Syphilis.+—­The constant upward tendency of recent estimates of the amount of syphilis in the general population, as a result of the application of tests which will detect even concealed or quiescent cases, is a matter for grave thought.  The opinion of such an authority as Blaschko, while apparently extreme, cannot be too lightly dismissed, when he rates the percentage of syphilitics in clerks and merchants in Berlin between the ages of 18 and 28 as 45 per cent.  Pinkus estimated that one man in five in Germany has had syphilis.  Recently published data by Vedder, covering the condition of recruits drawn to the army from country and city populations, estimate 20 per cent syphilitics among young men who apply for enlistment, and 5 per cent among the type of young men who enter West Point and our colleges.  It can be pointed out also with justice that the percentage of syphilis in any class grouped by age increases with the age, since so few of the cases are cured, and the number is simply added to up to a certain point as time elapses.  Even the army, which represents in many ways a filtered group of men, passing a rigorous examination, and protected by an elaborate system of preventions which probably keeps the infection rate below that of the civil population, is conceded by careful observers (Nichols and others) to show from 5 to 7 per cent syphilitics.  Attention should be called to the difference between the percentage of syphilis in a population and the percentage of venereal disease.  The inclusion of gonorrhea with syphilis increases the percentages enormously, since it is not infrequently estimated that as high as 70 per cent of adult males have gonorrhea at least once in a lifetime.