126 APPLIED BACTERIOLOGY 



Bollinger has estimated that the daily expectorations of 

 a phthisical patient when caseation is far advanced may 

 contain twenty million bacilli. 



In cases where phthisis is suspected, an examination of 

 the sputum should always be made, particularly as phthisis, 

 when taken in time, is very amenable to treatment. In 

 examining the urine in cases of suspected tubercular affec- 

 tion of the bladder, care must be taken in the collection of 

 the specimens to avoid contamination, as there is an organism 

 termed the Smegma bacillus, which is similar to the tubercle, 

 and behaves in the same manner to Gram's stain. It is not, 

 however, capable of growth on ordinary media, and hence 

 the application of Pastor's method as described above would 

 be conclusive. 



Occurrence and Distribution. — The disease is found all over 

 the globe, but is much more prevalent in cold and temperate 

 climates than in the tropics. The mortality due to tubercu- 

 losis is highest in March and April, and lowest in August 

 and September. 



The operatives in certain trades are especially liable to 

 be attacked by phthisis, particularly those in which there 

 is excessive moisture or gritty particles. 



The bacillus is conveyed by air, in the shape of dust ; by 

 food, such as milk, and possibly by meat. 



In the recently-issued Local Government report it has 

 been shown by feeding experiments that milk from cows 

 with tubercular disease of the udder is very infective, also 

 that the tubercle bacillus is not destroyed, if in the centre of 

 a joint of meat over six pounds in weight, by the ordinary 

 method of cooking. 



As has already been stated, the tubercle bacillus retains 

 its virulence for a considerable period of time on desiccation. 

 Messrs. Cadeac and Malet produced tuberculosis in guinea- 

 pigs by injecting material from the lung of a tuberculous 



