292 ORIENTAL PLAGUE chap. 



Third Series. — Urine. 



Experiment 14. — Turbid urine of a case of typhoid (end of second 

 week). An agar control culture was made with 1 loop of the 

 urine; it showed after incubation 36 colonies of various kinds of 

 microbes, chiefly belonging to the coli-typhoid group. To 70 ccm. 

 of the urine (practically the whole of the urine obtainable) O'l ccm. 

 izal was added ; this represents, therefore, 1 in 700. 



Cultures were made, using 3 loops for each culture tube, after 

 5, 15, and 30 minutes, with this result : — 



a. After 5 minutes : agar, no growth ; broth turbid. 



b. After 1 5 minutes : agar, no growth ; broth, no growth. 



c. After 30 minutes : agar, no growth ; broth, no growth. 

 From this experiment it appears that 15 minutes was sufficient 



for izal 1 in 700 to cause complete disinfection of this urine. 



Experiment 15. — Normal urine was filtered and then sterilised by 

 heating it for 10 minutes at 70° C. To the sterile clear urine added 

 of a recent culture of B. typhosus sufficient to produce slight 

 turbidity. One platinum loop of this was transferred to the surface 

 of gelatine. It brought forth a very large number of colonies of 

 the B. typhosus. 



a. To 50 ccm. of the typhoid urine was added 0*1 ccm. of izal, 

 this being equal to izal 1 in 500. 



b. To 60 ccm. of the typhoid urine was added 0*1 ccm. of izal, 

 this being equal to izal 1 in 600. 



c. To 75 ccm. of the typhoid urine was added 0*1 ccm. of izal, 

 this being equal to izal 1 in 750. 



After 5 minutes' exposure, cultures were made on agar and 

 broth, each tube receiving 3 platinum loops. Incubation 37° C. 

 The result was as follows : — 



a. 1 in 500, 5 minutes' exposure : no growth in either tube. 



b. 1 in 600, 5 minutes' exposure : no growth in either tube. 



c. 1 in 750, 5 minutes' exposure : good growth in both tubes, 

 proved to be pure B. typhosus. 



It follows from this that 1 in 600 for 5 minutes is the limit of 

 izai disinfection for B. typhosus distributed in urine. 



Experiment 16. — For control and comparison of the above 

 experiments sterile distilled water was substituted for the stools and 

 urine. In other respects all conditions remained the same ; namely, 

 of a recent culture of B. typhosus (same as used above) sufficient 



