Another factor in infant mortality is the hygienic surroundings, as revealed by statistical research. In BS° Meinert produced in Dresden a painstaking statistical work along these lines, devoted especially to the investigation of cholera infantum. His inquiry did not include all the deaths from diseases of the stomach and intestines, but was directed particularly to this form of cholera, with its characteristic symptoms. The value of this work arises from its careful collection of the data. Each case was elucidated by inquiry in the family and by determining the proper conditions for recovery.
Meinert has discovered, as the consistent result of all his inquiries, that the mortality from cholera infantum depends indirectly on the temperature of the air and directly on that of the dwelling. If the tem perature falls below 15° C. (40° F.), in the shade, the disease seldom, or never, appears; while long periods of high temperature greatly favor its increase. Meinert's statistics show that it is not 'solely the excessive temperature, or the lack of cubic space per capita, in the home, that occasions the high mortality. A total temporary cessation of spontaneous ventilation in the houses, arising from their construction and occurring only under certain barometric conditions in mid-summer, constitutes the decisive factor. The number of cases decreased at once with a strong wind and increased rapidly as soon as the wind fell again. Schlossmann objected to Meinert's idea from the standpoint of the general statistics of infant mortality. Prausnitz, on the other hand, has adopted Meinert's view, in so far as it accords to the home an important part in opening the way to digestive diseases in the earliest period. In doing this he relies on the statistics of Gratz, where each single case was made the subject of a special inquiry. Statistics have still much to accomplish along these lines. The goal will be reached more quickly if the individual istic method of Meinert and Prausnitz is adopted, and an inquiry is made in the case of every infant, into all the factors that have caused its death.
Incited by earlier researches, Prausnitz has recently made protracted statistical inquiries with the aim of determining the influence of pros perity on the mortality of infants dying from ailments of the stomach and bowels. The deaths have therefore been divided into four cate gories, in accordance ?vith a scheme proposed by Korosi.—(1) Rich,
(2) Middle-class, (3) Poor, and (4) Destitute,—and the percentage of deaths from these diseases has been calculated for each category. By this means it was shown that in Gratz, for example, in the last fifth of the past century not one child died in a rich family: while in the second category about -1 per cent., in the third 36 per cent., and in the fourth 60 per cent., fell victims to diseases of the stomach and bowels.
Analogous investigations in other cities give approximately the same result, as may be seen by Fig. 21. It is a \Veil fact that poor people have more children than the rich, and that therefore the children of the poor die in greater numbers. A supplement to the statistics, giv ing the number of deaths in each category, in proportion to the number of living is greatly to he desired. This is unfortunately impossi ble because there are no continuous records accessible \\ill Ch compare the number of living infants in the different cities those belonging to the respective categories. But the researches mentioned above are by no means rendered worthless by these defects. We must, however, be careful to draw from them only the conclusions which the statistics logically admit; namely, that there is a close relation between poverty and the high infant mortality from diseases of the stomach and bowels. This is a most important consideration in a choice of weapons for fight ing these diseases.
While, in all civilized countries, accurate tables of mortality are accessible and the accumulated data have been more or less thoroughly examined and criticized, there are no comprehensive statistics of disease. Means for ascertaining the pathological conditions of the population on a given day are lacking; so are also a continuous tabulation and utiliza tion for statistics of all cases of sickness among the people, together with their course and outcome. The creation of such statistics has pecu liar difficulties. Without the presence of a physician, a trustworthy determination of the sickness and its duration is impossible; physicians are not always called in; and, finally, the very classes which usually call a physician have little sympathy with his wish to use their own cases for literary purposes. Hence, the only systematic records are those of infectious diseases, of which notification is required by the authorities for hygienic reasons.