2 1 o INFECTION AND IMM UNITY 



which in tuberculosis and in influenza play an im- 

 portant part in the propagation of the disease. The 

 micrococcus of pneumonia may, however, retain its 

 vitality for a considerable time in dried masses of 

 sputum. It is destroyed by exposure for a few hours 

 to direct sunlight, and by a temperature of 140 Fahr. 

 within a few minutes ; also by all germicidal agents 

 in comparatively small proportion. The directions 

 already given for the disinfection of the sputa of pa- 

 tients suffering from tuberculosis or diphtheria apply 

 as well to the material expectorated by patients with 

 pneumonia, and this should never be neglected. 



The prevention of pneumonia will, to a large ex- 

 tent, depend upon the avoidance by individuals of 

 the predisposing and exciting causes of the disease. 

 Proper food, proper exercise, dress suitable to the 

 climate and season, avoidance of all excesses, and es- 

 pecially of the habitual use of alcoholic drinks, will 

 all tend to preserve the individual from infection by 

 the micrococcus of pneumonia. On the other hand 

 insufficient food, insufficient clothing, alcoholic ex- 

 cesses, insanitary surroundings, and a recent attack of 

 certain other infectious diseases (measles, influenza, 

 typhoid fever) are potent predisposing causes. Ex- 

 posure to cold, to draughts, or wet feet may, in con- 

 junction with the presence of the specific micrococcus, 

 become the direct exciting cause of an attack. 



