"In an analysis of the ratio of mortality in 266 German cities of about 15,000 inhabitants, it was found that the ratio of mortality per 100,000 of the living, before antitoxin was used, varied from 130 to 84 from 1886 to 1893, while the ratio from 1894 to 1897 varied from 101 to 35. It is a significant fact that during 1894, when, although antitoxin was used to a certain extent, it was not in general use, the ratio was 101; that when antitoxin was used more extensively, in 1895, the ratio was 53; that in 1896 it was 43; that in 1897, when antitoxin was very generally used, the rate fell to 35." (_Trans. Massachusetts Med. Soc._, 1898.) "Dr. Gabritchefski points out that in recent years the number of persons (in Russia) attacked by the disease has increased, the figures for the whole of Russia rising from about 100,000 or 120,000, ten years ago, to considerably over 200,000 in 1897. The introduction of the serum treatment has, however, had a marked effect on the mortality of the disease; and the actual number of deaths from diphtheria has either not increased at all, or has slightly diminished." (_Lancet_, 5th Aug. 1899.) Of course there will still be bad diphtheria years and good diphtheria years: for example, the death-rate of the population of England, from diphtheria, was higher during the years 1893-1899 than during the years 1889-1892. Antitoxin can no more prevent a bad diphtheria year than an umbrella can prevent a wet day. But in limited outbreaks of diphtheria, such as occur in a village, an asylum, a school, or a large family of young children, it can be used, and is used, as a prophylactic, and with admirable results. The example of Dr. Kármán, just quoted, is one of the earliest instances of this preventive use of antitoxin: other instances, of equal importance, are given in the _Boston Medical and Surgical Journal_, December 1897 and March 1898; and in the _Lancet_, 2nd April 1898, and 28th January 1899. A summary of later experiences of this preventive use of antitoxin in different countries is given by Dr. Wilcox of New York, and Dr. Stevens of Philadelphia, in Gould's _Year-Book_ for 1902:--