TUBERCLE 63 



Remember that they should be left in alcohol for a quarter of 

 an hour or so after staining. 



Pus is best carbolized in the same way as sputum ; if very 

 thin it may be treated like urine. The tubercle bacilli will 

 rarely be found in pus unless it is examined soon after the 

 abscess is opened, but may be detected by inoculation experi- 

 ments for long periods. 



Clear exudates axe more difficult to examine, and, as they usually 

 contain bacilli in very small numbers only, a negative result 

 should not be given too much weight. (For the best method to 

 employ, see p. 121.) The examination is best made in a bacterio- 

 logical laboratory, as decisive results can only be obtained by 

 animal experiments. Collect the fluid in a bottle which has 

 previously been boiled in water for half an hour and allowed 

 to cool. Cork it with a cork which has also been boiled. 

 Add no antiseptic, and forward it to the laboratory as soon as 

 possible. 



Milk may be examined in the same way as urine, films being 

 made from the cream as well as from the deposit. These films 

 are fixed, soaked in ether to remove fat, and again fixed. They 

 are then stained as before, and it is advisable to pass them 

 through alcohol. 



The results obtained by this examination are somewhat un- 

 certain, as some of the other acid-fast bacilli found in milk are 

 almost exactly like the tubercle bacillus, and animal experiments 

 are necessary for definite proof. 



When fieces are to be examined, the best plan is to administer 

 opium in amount sufficient to cause constipation. The surface of 

 the scybalous motions which result are to be scraped off and 

 stained in the usual way. 



Interpretation of Results. 



The finding of tubercle bacilli in the sputum is conclusive 

 evidence of tuberculosis of the lungs, but no information as to 

 prognosis can be drawn from the numbers which are present ; 

 they may occur in great quantities in the sputum from patients 

 who are doing well, and the author has found enormous numbers 

 in the sputum of a person who had presented no symptoms of the 

 disease for eight years, and was apparently cured. But a person 

 in whom the bacilli are present is always in danger of a re- 



