Page:Popular Science Monthly Volume 85.djvu/21

Rh The danger of contact infection from such gross discharges as the sputum are sufficiently obvious. Material of quite as dangerous a nature is thrown out from the mouth as a fine spray in coughing, sneezing or loud speaking. Furthermore, it is a sad fact that cleanliness in a bacteriological sense is a very rare thing and the hands are usually more or less soiled with discharges from the nose and throat and too often from the intestines as well. Dr. C. V. Chapin, in his classic book, on "The Sources and Modes of Infection," has some striking paragraphs which, though not pleasant reading, must be pondered by all who would really understand how communicable disease is spread.

The control of contact transmission, the breaking of the chain of communication between the infected and the non-infected person, involves one or both of two measures. On the one hand, the spread of infective material from sick persons and carriers must be checked, so far as possible, and, on the other hand, the mouths of well persons must be guarded against infective material which, despite all our efforts, will to some extent be distributed in the world about us. The first half of this task involves the recognition of the sources of danger, and is of course greatly complicated by the presence of the unrecognized carriers. Much may be hoped, however, from the development of what may be called the sanitary conscience, the recognition on the part of each man, woman and child of the grave responsibility which he may incur by