342 THE TUBERCLE BACILLUS 



of accomplishment. Under strictly aseptic conditions, Bergeron has re- 

 peatedly failed to detect the presence of tubercle bacilli in blood by Jousset's 

 method. 



(a) Bezangon and Griffon's method. To 5 c.c. of blood add 5 c.c. of distilled water 

 and 5 drops of soda and triturate the mixture in a mortar until completely dissolved. 

 Then add 20 c.c. of water and boil in a porcelain dish for 5 minutes. Centrifuge 

 the product for 10 minutes, prepare films and stain with carbol-fuchsin. 



(&) Jousset's method (Inoscopy). To 30 c.c. of blood add 100 c.c. of distilled 

 water. Digest the clot with artificial gastric juice (p. 340) for 2 or 3 hours in the 

 warm incubator (38 C.). Centrifuge the product, stain the deposit with carbol- 

 fuchsin, and examine it for tubercle bacilli. 



(c) Nattan-Larrier and Bergeron's method. In this method the blood is 

 received direct from the vein into twenty times its volume of sterile distilled 

 water ; the blood hsemolyses ; the haemolyzed mixture is centrifuged and the 

 deposit examined for bacilli. 



(d) Blood may be collected in sodium citrate solution to prevent it clotting, 

 centrifuged and the deposit examined. Lesieur utilizes the anti-coagulating 

 property of the digestive juices of leeches. A leech is put on the patient and 

 when gorged with blood it is pressed and the product centrifuged. 



C. Pus. 



In pus from a tuberculous lesion the bacilli are present in small numbers 

 only so that search for the organism in films often has a negative result. One 

 or other of the methods of homogenization described above when dealing 

 with sputum may with advantage be adopted, though it is always pre- 

 ferable to inoculate a guinea-pig. The tubercle bacillus in the majority of 

 cases occurs in pure culture in tuberculous pus but in other cases it may 

 be associated with the ordinary pyogenic organisms and particularly with 

 staphylococci. 



D. Exudates. 



In the sero-fibrinous exudates which occur in pleurisy, peritonitis, peri- 

 carditis, etc., direct examination for the tubercle bacillus by microscopical 

 examination always gives negative results. 1 



Jousset appears to have obtained remarkable results by applying the 

 method of inoscopy to the detection of the tubercle bacillus ; he found the 

 bacillus in all sero-fibrinous exudates. Unfortunately this method involves risk 

 of error by reason of the presence of acid-fast bacilli in the surrounding air 

 (p. 341) and the bacilli stained by Jousset were, at least in most cases, evidently 

 not the tubercle bacillus. Jousset himself noted their abnormal forms and 

 the ease with which they were decolourized by too long immersion in acid 

 (p. 345). Moreover, the method of inoscopy usually gives negative results 

 when it is applied under strictly aseptic conditions (Bergeron). 



Jousset's technique. If the liquid be spontaneously coagulable it is allowed to 

 clot and the clot treated as described above in the case of blood. When the liquid 

 does not coagulate spontaneously (cerebro-spinal fluid, for example) some horse- 

 blood plasma is added to form a clot and this is then treated in the ordinary way. 

 Horse plasma is obtained by mixing equal volumes of horse- blood and 10 per cent, 

 solution of sodium chloride, centrifuging and collecting the supernatant fluid. 



Satisfactory results may be obtained by sowing the exudate on blood- 



P Though this statement is true in the majority of cases its application is not so universal 

 as the author's experience would lead him to think. Microscopical examination of fluid 

 from cases of tuberculous pleurisy may show the presence of tubercle bacilli and occa- 

 sionally in extraordinarily large numbers.] 



