274 ATMOSPHERE IN RELATION TO HUMAN LIFE AND HEALTH. 



virulence, still, in order to avoid the setting up of fresh centers in sus- 

 ceptible people, disinfection and washing are indispensable. 



The most remarkable instance of immunity from infection of a mater- 

 nity hospital is that of the Grand Duchess Catherine, at St. Peters- 

 burg, one of the most carefully regulated in the world. Every utensil, 

 instrument, and article of clothing is rendered aseptic and kept so. A 

 vacated room is at once stripped and disinfected. The floors are mosaic 

 concrete, the walls tiles and parian cement. Floors and walls are thor- 

 oughly washed. The result of this extreme care was that during three 

 years there was only one case of puerperal fever, and that was brought 

 in from outside. 



A boiled vegetable or animal infusion in a test-tube may be kept an 

 indefinite time without change or fermentation when ordinary air and 

 objects are excluded, but a mere touch of the finger or of some object 

 which has been lying in a room infects with microbic life and the fluid 

 goes bad. The comparative infrequency of the conveyance of some of 

 the infectious diseases from one to another by means of a third person 

 is less due to the absence of the germs than to the average resisting 

 power of the human body. The precautions taken to prevent the 

 spread of foot-and-mouth disease in sheep and cattle well illustrate 

 what is necessary for the protection of human beings. In an outbreak 

 in England in 1892, a strict watch was kept to prevent the passage of 

 any infected article, and no one was permitted to come in contact with 

 cases of the disease excepting those persons who were provided with 

 a proper dress, which could be easily disinfected. If these and similar 

 measures had been customary for some years for the prevention of 

 epidemics in man, the belief in an "epidemic constitution of the atmos- 

 phere" or in "aerial transmission" by wind for long distances could 

 hardly have survived. The recent pandemic of influenza has given 

 occasion for the revival of these hypotheses, which were successively 

 overthrown in relation to consumption, the plague, cholera, yellow 

 fever, smallpox, and even rabies or hydrophobia. Recent investiga- 

 tions have, however, proved beyond all doubt that the atmosphere does 

 not, except possibly in the rarest instances, convey the virulent matter 

 of epidemics from place to place, and that there is no security against 

 infection so great as life in the open air and good ventilation. In fact, 

 the atmosphere is the great reservoir of purifying agents and the most 

 important of all disinfectants. In close places the air, deprived of some 

 of its oxygen, filled with moisture and the impurities of respiration, 

 can not exercise its beneficent function, and in crowded rooms infec- 

 tion becomes easy. So, also, cholera and other infectious matter retains 

 its virulence in packages or stored clothing. Under the open sky 

 and in pure air few species of pathogenic germs can pass many feet 

 unscathed. 



Consumption is typical of the class of endemics which can be caught 

 either directly from a patient or indirectly through infected objects in 



