TUBERCULOSIS AND THE PUBLIC HEALTH. 1055 
disease, and this mode of infection must be extremely rare. It 
is the predisposition which is so often confounded with the trans- 
mission of the disease. The chief modes of communication are 
inhalation and ingestion; but the disease may be inoculated, 
The bacilli may be received from the air by inhalation, and from 
tuberculous food, such as milk or meat, by ingestion. Probably, 
in adults at any rate, inhalation is the chief mode, and next to 
that ingestion. 
There ave some who doubt the identity of human and bovine 
tuberculosis; but there are on record numerous instances of 
infection from human beings to lower animals, from one animal 
to another, and from the lower animals to man. Where cattle 
are few or absent, consumption exists in man to a such smaller 
extent. Where cattle are numerous, or are kept in the houses, 
tubercular diseases are frequent both in man and the lower 
animals. Dr. Creighton believes that the peculiar errors of 
nutrition in the domesticated bovine species all over the world 
are the real fountain and source of human tubercle. 
That tuberculous milk may, and frequently does, cause tuber- 
culosis in human beings is beyond all doubt. The milk con- 
taining the tubercle bacilli enters the mouth and passes on to the 
throat. During the time of its passage the bacilli may be 
deposited in the mouth, tonsils, pharynx, or adjacent structures, 
More bacilli are added every two, three, or four hours, according 
to the frequency of feeding. These bacilli may be washed further 
down and into the stomach, or may cause infection in the mouth, 
&e., or may be inhaled into the lungs. The milk that passes 
into the stomach may deposit more bacilli, or may continue on its 
journey into the intestines. Strauss and Wiirtz have shown that 
the bactericidal quality of the gastric secretions is insufficient to 
destroy the bacillus tuberculosis. Infection may thus arise in the 
mouth, tonsils, throat, lungs, or intestinal canal from tuberculous 
milk. The lung infection may be primary from direct inhalation 
of the bacilli lodged in the mouth, or may be secondary to infev- 
tion of other parts. 
Woodhead reports that in 127 cases of tuberculosis in children 
that he examined, tubercular ulceration of the intestine was found 
in 43 ; whilst in 100 cases, or nearly 79 per cent. of the whole, 
the glands connected with the intestinal tract were in some stage 
or other of tubercular degeneration. He argues that tuberculosis 
connected with the intestine is of frequent occurrence in children, 
and that the infection frequently takes place by the alimentary 
canal. The age at which these tubercular glands were found is 
very significant. During the first year of life there were 4 cases ; 
from 1 to 24 years, 33; from 3 to 54 years, 29; from 6 to ng 
years, 12 ; from 8 to 10 years, 13; and from 11 to 15 years, 9 
cases. In 14 cases these glands only were affected. 
