Viability of B. typhosus. 



37 



had been fed regularly on a ration of rolled barley and succulent 

 grass. 



No animal was classed as a carrier unless it had been inoculated 

 with B. typhosus at least two weeks previously since it was felt 

 that time sufficient for physiological adjustment should be given. 

 This period is arbitrary but is conservative since between one and 

 two weeks are required before the weight curve of the animal 

 commences to ascend. Rabbit carriers were prepared according 

 to the method of Gay 1 and Claypole 2 which in this series yielded 

 ioo per cent, efficiency. No bile was classed as having been taken 

 from a positive carrier unless subsequently B. typhosus was isolated 

 from it and confirmation made by agglutination. 



A series of nine rabbit biles from experimental carriers yielded 

 a mean hydrogen ion determination by the colorometric method 

 of P H 8.33. A check series of twenty-seven units taken from 

 normal animals gave a mean reading of P H 7.41. The factor of 

 variability for the first series taken from carrier animals is 6.4 

 per cent, while the like factor from the larger check series is 2.3 

 per cent. The two therefore are comparable. 



No reason thus far is assigned for this difference in P H of the 

 two series of fluids. It is felt that a possible explanation based 

 on lysis of cells in the course of the inflammatory process with 

 increase in alkalinity is not sufficient since the lowered hydrogen 

 ion concentration which may be expected to result should be 

 expected to occur earlier were it the cause. The lowered P H 

 was most evident ten days following preparatory injection of the 

 typhoid organisms. 



The results obtained for normal rabbit bile coincide with those 

 of Quagliariello 3 but are somewhat higher in the concentration 

 of the hydrogen ion than those given by Okada 4 who however was 

 working with hepatic rather than with cystic bile. 



Relative to these observations it may be stated thatB. typhosus 

 will live for at least 24 hours in ox bile the reaction of which after 

 autoclaving is altered to P H 9.2 by the addition of an appropriate 



1 Gay, F. P. and Claypole, E. J., Archiv. Int. Med., 1913, xii, 613. 



1 Nichols, H. J., Jour. Exp. Med., 1916, xxiv, 495-514. 



•Quagliariello, G., Atti d. Reale Accad. d. Lincei, 1911, xx, Ser. 5a, 302-305. 



♦Okada, S., Jour. Phys., 1915, 1, 114-118. 



