320 



Mr. C. Russ. 



[May 21, 



My colleague, Dr. Fletcher, prepared an emulsion of tubercle bacilli in 

 water, and standardised to contain 1000 bacilli per cubic centimetre ; he 

 thoroughly mixed \ c.c. {i.e. 500 " T. B.") of this emulsion with 100 c.c. of 

 normal urine. Allowing this mixture to stand for 24 hours in a conical 

 vessel to assist sedimentation of the bacilli, he then siphoned off' the super- 

 natant three-quarters of its volume ; the remainder was centrifugalised 

 (1/8 H.P. electric centrifuge) three times. In a stained preparation from the 

 final deposit he found no tubercle bacilli. I added ^ c.c. {i.e. 500 tubercle 

 bacilli) of the same emulsion to 50 c.c. of normal urine, and made up the 

 volume to 100 c.c. by adding bromic acid, lactic acid, and ethylamine, and 

 thoroughly shaking the mixture. This mixture was electrolysed in the 

 vessel illustrated in fig. 3. After 21 hours' electrolysis 128 tubercle bacilli 

 were counted in the stained preparations made from the trap contents. 



Detection of " T. B." in Tuberculous Urines by the Centrifuge and Electric 



Current. 



Case. 



Centrifuge. 



Electric current. 



Volume of 

 urine used. 



Description of 

 " T. B." seen in 

 films. 



Volume 

 used. 



No. of 

 times 

 diluted. 



No. of " T. B." seen 



in film but which 

 is not a total count. 



1 



2 

 3 

 4 

 5 

 6 

 7 

 8 

 9 

 10 

 11 

 12 



c.c. 

 10 

 30 

 repeat 

 20 

 20 

 20 

 20 

 10 

 10 

 10 

 10 

 10 



Moderate numbers ... 



,, ... 



Fairly numerous 



Fairly numerous 



c.c. 



10 



10 

 7 

 6 

 6 

 6 

 2 

 5 

 5 

 5 

 5 



10 



15 



5 

 6 

 7 

 7 

 7 



21 

 9 

 9 

 9 

 9 



10 



bacilli. 



59 



38 

 205 



84 

 149 

 103 



15 



22 



68 



35 



40 



65 



The volume used by centrifuge = 10 c.c. once, twice or thrice repeated ; i.e. the capacity of ths 

 tube = 10 c.c. 



The film forms a permanent record of the experiment in each oase. 



These experiments concluded by repetition of this process in 12 cases, 

 using always tuberculous urine, in which the bacilli had been previously 

 found by the centrifuge. During these cases, variations of the time the 

 current passed and of its strength were introduced. The results are 

 collected in Table III, the main conclusions being : — 



(1) Tubercle bacilli were obtained in the trap upon the conclusion of 

 every test. 



