290 BACTERIA 



The parts affected are the mucous membrane of the fauces, 

 larynx, pharynx, trachea, and sometimes wounds and the 

 inner wall of the stomach. The common sign of the disease 

 is the membrane in the throat ; but muscle weakness, 

 syncope, albuminuria, post-diphtheritic paralysis, convul- 

 sions, and many other symptoms guide the physician in 

 diagnosis and the course of the disease. 



The Bacillus diphtherice was isolated from the many bac- 

 teria found in the membrane by LofHer. Klebs had pre- 

 viously identified the bacillus as the cause of the disease. 



or moist, infection cannot take place. It is, of course, better to destroy it 

 completely. As for milk and meat, boiling the former and thoroughly cook- 

 ing the latter will remove all danger. 



11. The expectoration is infective. This is one of the commonest modes of 

 infection, and to it is held to be due the large amount of respiratory tubercu- 

 losis (consumption, phthisis). The expectoration from the lungs must contain, 

 from the nature of the case, a very large number of bacilli. As a matter of 

 fact, a single consumptive individual can cough up in a day millions of tuber- 

 cle bacilli. When expectoration becomes dry, the least current of air will 

 disseminate the infective dust, which can by that means be readily reinspired. 

 Expectoration on pavements and floors, as well as on handkerchiefs, may thus be- 

 come, on drying, a source of great danger to others. The discharges from the 

 bowels of infants suffering from the disease also contain the infective material. 



12. Milk, though a much more likely channel for conveyance of tubercle 

 than meat, is only or chiefly virulent when the udder is the seat of tuberculous 

 lesions. The consumption of such milk is only dangerous when it contains a 

 great number of bacilli and is ingested in considerable quantity. Practically 

 the danger from using raw milk exists only for those persons who use it as 

 their sole or principal food, c. g,, young children. All danger is avoided by 

 boiling or pasteurising the milk. 



At the same lime there is an increasing amount of evidence forthcoming at 

 the present time which goes to prove that milk is not infrequently tainted with 

 tubercle (see p. 195). The tuberculin test should be applied to all milch cows, 

 and the infected ones isolated from the herd. Milk supplies should be more 

 strictly inspected even than cowsheds. 



13. There are several methods by which meat infection can be prevented. In 

 the first place, herds should be kept healthy, and tubercular animals isolated.* 

 Cowsheds and byres should be under sanitary supervision, especially as 

 regards overcrowding, dampAess, lack of light, and uncleanliness. Public 

 slaughter-houses under a sanitary authority would undoubtedly be most ad- 



