TUBERCULOSIS. 
561 
and be reduced to a powder, and the bacilli be lifted into the 
air, from which it is inhaled. Only such bacilli as withstand 
the drying process can enter this way, and it must be re¬ 
membered that the tubercle bacilli has a great power of with¬ 
standing this drying process. This theory, as against the 
other, that the bacteria free themselves from where they are 
contained and are carried upward by the air or by evapora¬ 
tion, has been clearly proven by a series of beautiful experi¬ 
ments related by Fraenkel in his book on bacteriology. 
Dust collected from a dwelling where dwelt a phthisical 
patient produced tuberculosis in a guinea-pig. Dust 
taken from a place where there was no consumptive pro¬ 
duced negative results. It was found that the dried sputa 
found in the pocket handkerchiefs of consumptives was 
a prolific source of the bacteria. As I have already indicated, 
every consumptive is a source of danger to the health of 
animals as well as to the people around him. 
The bacilli having gained access to the body by reason of 
their biological quality, they originate an irritation resulting 
in a true inflammation. It is then that a struggle between 
the cells of the tissue on the one hand and the bacilli on the 
other takes place, and the result is determined by the 
vitality of the cells or the infectiousness of the bacilli. Should 
the cells conquer, the bacilli are destroyed before they can 
do any injury, but if the bacilli conquer, the result is well 
known. 
It may interest us to glance at the theory of phagocyto¬ 
sis. Phagocytes are formed of leucocytes and fixed connec¬ 
tive tissue cells. They are of two kinds, the large and the 
small. It seems to be the duty of these elements to fight the 
battle on behalf of the organism against the invasion of the 
bacilli. As soon as the irritation is set up they hasten to the 
battlefield, and the fight is on to the death. The phagocytes 
endeavor to devour the invaders, to digest them and render 
them sterile. It seems that certain bacilli do not require the 
whole force of the phagocytes. For instance, the strepto¬ 
coccus of erysipelas can be overcome easily by the small 
phagocytes, as can other micrococci; but in the case of tubercle 
