THE GREAT WAR IN THE ZONE OF THE ARMY. 321 



sanitation, or the sanitation of an open battlefield, as the case might 

 be. He has a divisional water-supply officer on his staff. He keeps 

 a close watch on diseases which might become epidemic in his com- 

 mand and in epidemics works in cooperation with the chief sanitary 

 officer of the Army. He is in close touch with Army laboratories 

 and calls on them for special work. 



Epidemiology, 



The classification of communicable diseases and the administpa- 

 tion of the epidemiologic service is based on an exposition of this 

 subject made before the Arm,y Sanitary School in Langres by 

 Colonel Hans Zinnser, chief sanitary officer of the Second Army. 

 This officer was W'Orking out these plans when the war came to a 

 close and to him w'e are indebted for a prominent part in a great 

 reform. 



The Army chief sanitary officer should be an epidemiologist and 

 laboratory man, as well as an administrator. He should keep spot 

 maps showing the prevalence and source of infectious disease. In 

 this he is largely dependent upon his section chiefs and divisional 

 sanitary officers. He should have a stationary laboratory capable 

 of becoming mobile at headquarters of the field Army, with two 

 traveling motorized laboratories to dispatch to special work. I am 

 not in accord with Colonel Zinnser in depriving a division of its 

 mobile laboratory, but these two motor laboratories can be kept busy 

 reinforcing division laboratories and checking their work. In- 

 fectious diseases are roughly divided into, (i) those disseminated 

 by the respiratory tract : Pneumonia, influenza, measles, scarlet 

 fever, meningitis, mumps, smallpox and chickenpox. (2) Those dis- 

 seminated by the intestinal tract : Typhoid and its congeners, the 

 dysenteries, simple diarrhea, etc. (3) Insect-borne diseases: trench 

 fever, typhus, malaria, scabies, etc. 



Communicable diseases depend for their extension either on the 

 susceptibility of the individual or upon means and methods of trans- 

 mission. For the first, such as meningitis and pneumonia, general 

 hygienic measures were enforced with a degree of insistence and 

 elaborateness of detail dependent upon the circumstances and serious- 



PROC. AMER. PHIL. SOC, VOL. LVIII, U, AUG. 12, I9I9, 



