* See pages 210 and 237, loc. ext.

** "Zeitschr. f. Schulgesundheitspflege," 1890, p. 505.

*** "Revue mens, des maladies de l'enf.," 1890, p. 144; cf. Ripperger, loc. cit. p. 205 ff.

§ A fact which cannot be simply neglected, as several enthusiastic contagionists have done. See the curve (Plate VIII), and also the instructive curves of Ripperger.

1889, in Paris (see p. 576). We may add the following examples: In the Baltic mill at Neumiihlen, near Kiel, within two to three days, out of 350 workmen, 150, or 43 per cent., were affected. At the machine factory in Muhlhausen, in Alsace, with from 3000 to 4000 workmen, 750 were attacked in a single day. In the industrial school at Swinton, near Manchester, during an epidemic of thirteen days, of 589 children living in the same rooms, 171, or 29 per cent., were affected, and in the following sequence: first day, 5; second day, 71; third day, 30; fourth day, 7, etc.

Of course, these examples in no wise contradict the contagion theory; they seem, however, to prove that the germs in isolated districts were occasionally aerodromic, and were able to produce simultaneous infection in large numbers, or, in other words, sudden affection of the masses.

Simple, uncomplicated influenza is a disease which is but rarely dangerous to life. Since in an epidemic the number of uncomplicated cases is very high in comparison with that of the cases which end fatally from complications, the mortality in comparison to the incidence is very slight.

The mortality in the epidemic of 1889-1890 was as follows: In Munich (22,972 cases), 0.6 per cent.; in Rostock (3568 reported cases), 0.8 per cent.; in Mecklenburg-Schwerin (21,000 cases), 1.2 per cent.; in Leipsic (12,769 cases), 0.5 per cent.; in the Germany army (55,263 cases), 0.1 per cent.; in Karlsruhe (43,000 cases), 0.075 per cent.; and in 15 Swiss towns, 0.1 per cent.

But such statistics have only a slight value, and they do not give a correct representation of the mortality produced by influenza, because the numerous fatal complications and sequelae, especially the deadly influenza pneumonia, are not included, as they should be, in the influenza mortality. But the deaths from these causes appear very plainly in the rise of the general death rate.

Everywhere, soon after its epidemic development, influenza produced an increase, and almost everywhere a sudden increase, in the death rate. The date of this sudden rise of the total mortality proved a valuable aid in determining the time of the outbreak of the epidemic in the different cities of Germany, as P. Friedrich has shown in his statistical investigation.

Naturally this is not the place to go into statistical tables, but a few examples of some of the large cities may be quoted to show the general increase in the mortality at the height of the epidemic of influenza. If we compare the highest, therefore the acme of the influenza epidemic of 1889-1890, that is, the weekly mortality number* with the same week of the year 1888-1889, which was free from the epidemic, we have the following comparative figures for these cities:

Berlin, 20.6:37.7; Hamburg, 24.2:32.1; Breslau, 29.2:30.0; Leipsic, 20.7 : 41.7; Munich, 24.6 : 48.6; Cologne, 31.9 : 52.2; Dresden,

* Calculated for 1000 inhabitants and for the year.

19.5 : 38.8; Frankfort a. M., 20.2 : 41.4; Kiel, 23.3 : 69.6; Strassburg, 24.8 : 52.5; Stuttgart, 23.1 : 49.0; Brussels, 29.5 : 52.4; London, 24.9 : 32.4; Paris, 22.3 : 61.7; Vienna, 52.8 : 45.9; and in 15 Swiss towns, 23.1 : 47.9.

The following table shows the total number of deaths in Paris, arranged by weeks for the years 1888-1889, in comparison with the epidemic years 1889-1890. The numbers in Paris were*:

The increase in mortality during an epidemic of influenza, as shown by the statistics, is mainly due: First, to an increase (in some cities nearly double) in the mortality from acute diseases of the respiratory organs, and, secondly, to an appreciable rise in the death rate from pulmonary tuberculosis. ***

With the disappearance of the epidemic a slight diminution in the general death rate and partly also in the mortality from acute diseases of the respiratory tract may be noted. The mortality from pulmonary tuberculosis especially fell so low that the total mortality from this affection in the year 1890 showed no increase, or only a slight one, above the average. Many phthisical patients who would have died in the epidemic year only succumbed somewhat sooner from the prevalence of influenza than they would have done without its influence.

The increase in the general mortality during the influenza epidemic furnishes the best standard for estimating the total number of deaths. This calculation has been attempted with the help of the increase in the general mortality. Sperling, basing his calculation on the mortality tables of 200 German cities (11,500,000 inhabitants), found that in the whole of Germany (49,500,000 inhabitants) about 66,000 persons succumbed to the epidemic of 1889-1890 (or 1 per 1000 of the population).

Not only in the number of deaths does influenza show its influence upon the population, but, like all great epidemics, it also has an influence in diminishing the number of births. A. Bloch showed that in France the number of births in the epidemic year of 1890 was 42,500 less than in 1889. The decrease in the number of births occurred especially in the months of September and October, 1890, corresponding as regards conception to December and January, at which time the disease prevailed in France. In the earlier months the disturbing influence of influenza upon pregnancy shows itself in abortions and miscarriages. A similar influence on the birth rate was shown to exist for Germany by Sperling and Friedrich; for Bavaria, by Stumpf; and for Switzerland, by Schmid.

Sperling showed that in the epidemic year (1890) there were 18,800 >births less than in an average year. He calculates that through the influence of influenza in 1889-1890 the total loss of life (deaths plus decreased births) in Germany amounted to 85,100 individuals.