Q. 4898, 
5098, 8085, 
8808 
Paragraphs 
24, 69, et 
seq. 
Food of the 
baciilus. 
Animals 
attacked. 
Circum- 
stances pre- 
disposing an 
animal to 
attack. 
‘vated artificially upon various purified, i.e. sterilised, animal fluids, such as the serum 
xX COMMITTEE ON PLEURO-PNEUMONIA AND TUBERCULOSIS : eae 
they will not grow although they may fall upon a suitable soil. On the other hand, 4 
they will not be killed, and, moreover, the temperature of some dairy sheds in the 
summer may approach the point at which the development of the organisms outside 
the body would be possible. It is only, therefore, under these latter circumstances ; 
to be feared that in this country these tubercle microbes will grow and develop 
outside the body. i 
9, The other condition, drying, is, in the case of most microbes, a very important ee 
one, since few resist dessication. Numerous experiments, however, have been made 4 
upon expectoration containing the bacilli. Such expectoration has been dried during 
very considerable periods, viz., several months, and has also been successively dried 
and moistened for similar periods, and yet the bacilli have not been killed, and when 
inoculated into animals they have actively produced the disease. peice 
10. It is abundantly evident, therefore, that the infectious discharges of a tubercular 
animal remain actively virulent in this climate for a long time after they have been Be 
cast from the body, and that stalls and sheds may thus become a source of danger 
unless thoroughly cleansed. een? 
11. The bacillus, under ordinary circumstances, of course flourishes upon the living» Se 
tissues of the animal it attacks, but its discoverer, Koch, showed that it could be culti- _ 
of blood, &e. 
12. The tubercle bacillus does not attack all domesticated animals equally. . ang- . 
ing them in order of respective liability to the disease, they are as follows :— ft QU 
Mani Goats. 
Milch cows. Sheep. Wasa 
Fowls. Horses. . eo 9 ae 
Rodents. Carnivora, #.e., dogs, cats, &c. (very rarely). — 
Pigs. Seed 
13. From this it appears that the organism grows most readily. in those animals 
which are omnivorous and herbivorous. e 
14. In all cases the female sex suffers more than the male, and in certain formsof 
the malady, as is common to all microbe diseases, young animals are more sensitive — 
and more easily attacked than adults. bier 
15. Further, certain unhealthy conditions cause a predisposition to contract the 
disease and receive the poison. Such are— cb OE ee ae 
(1.) Starvation. ee oh ae 
(2.) Deficiency of oxygen by bad ventilation. : apt BRANES ai 
(3.) Exhausting secretions, e.g., prolonged lactation. Pa Eat at: 
(4.) Possibly heredity (vide infra, Modes of transmission of the virus, Art. 29). 
(5.) Certain foods (asserted, but very doubtful). EA 
16.—(1.) Of these, starvation is very important, since it causes degeneration of a: 
the tissues, and diminishes thereby their resistance to the growth of the parasitic — 
microbes. Ahr 
17.—(2.) The deficiency of oxygen by want of ventilation has been for very many _ 
years recognised to be a fertile source of predisposition to tubercular infoononr aan 
to be very favourable to the transmission of the virus from one individual to another. — 
This is so notorious that reference need only be made to the instances recordedin 
works on Hygiene to substantiate the statement. . 
18.—(3.) Exhausting production of milk can be easily understood to effect, as seen’ 
in the gradual emaciation, &c. of milch cows by the constant loss of the fat, albumen, — 
and salts contained in the milk, just those degenerative changes which reduce the 
vital resistance of the animal. It is consequently very probable that the especial 
proclivity of milch cows to contract the disease is, to a considerable extent, due to 
this factor as well as to that expressed in Article 17. eye 
19.—(4.) The well-known influence of heredity in perpetuating tuberculosis among __ 
stock is attributed by some to the transmission from parent to offspring, not of the 
actual virus, but of a condition of tissue which is peculiarly favourable to the develop- 
ment of that organism. This view is naturally but a hypothetical one. Still, as it is 
held by many authorities, it is here stated. See also Arts. 28, 29, 30, 31, 32, and33. 
20.—(5.) Some foods, 7.¢., grains, &c., have been imagined to favour the occurrence - g 
of tuberculosis, but this is extremely problematical, 
