3 1 PA THOGENIC BA CTERIA . 



bedroom occupied by a consumptive before it becomes 

 the chamber of a healthy person. 



Boards of health are now becoming more and more in- 

 terested in tuberculosis, and, though exceedingly slow 

 and conservative in their movements, are disseminating 

 literature among doctors for distribution to their patients, 

 with the hope of achieving by volition that which they 

 would otherwise regard as cruel compulsion. 



The channels by which the tubercle bacillus enters the 

 organism are varied. A few cases are on record where 

 the micro-organisms have passed through the place7ita, 

 so that a tuberculous mother was able to infect her 

 unborn child. It is not impossible that the passage of 

 bacilli in this manner through the placenta causes the 

 development of tuberculosis in infants after birth, the 

 disease having remained latent during fetal life, for 

 Birch-Hirschfeld has shown that fragments of a fetus, 

 itself showing no tubercular lesions, but coming from a 

 tuberculous woman, caused the death from tuberculosis 

 of guinea-pigs into which they were inoculated. 



The most frequent channel of infection is the respira- 

 tory tract, into which the finely-pulverized pulmonary dis- 

 charges of consumptives and dust of infected rooms and 

 streets enter. Fliigge, Laschtschenko, Heyman-Sticher, 

 and Beninde x find that the greatest danger of infection 

 is in the atomized secretions of the tuberculous respira- 

 tory apparatus, discharged during cough. Nearly everyone 

 discharges finely comminuted secretions during cough- 

 ing and sneezing, as can easily be determined by holding 

 a mirror before the face at the time. Even though dis- 

 charged by consumptives these atoms of moisture are not 

 infectious, except when tubercle bacilli are present in 

 the sputum. Experiment showed that they usually do 

 not pass further than 0.5 meter from the patient, though 

 occasionally they may be driven 1.5 meters. The impor- 

 tance of a knowledge of these facts in dealing with tuber- 

 culous individuals is very great, and teach us that visits 



1 Zeitschrift fur Hygiene, etc., Bd. xxx., pp. 107, 125, 139, 163, 193. 



