364 Mr. Plimmer and Capt. Fry. Further Results of [June 28, 



Dilutions of lithium antimonyl tartrate in 0'89 per cent, salt solution 

 mixed with Surra rat's blood, in equal parts. 







Dilutions. 



















Time. 



Control. 













1—500. 



1—1000. 



1—5000. 



1—10,000. 



1—20,000. 







Motion- 

 less ' 



Motion- 

 less 



Some active 

 trypanosomes 



Active trypanosomes 



Yery active 

 trypanosomes 



1 min. 



Very active. 





» 



Motionless 



Some active 

 trypanosomes 



Many active 

 trypanosomes 



10 mins. 



>> 



» 





3) 



Practically no motile 

 trypanosomes seen, 



only 1 or 2 in a slide. 

 Tendency to clump 



Few active 

 trypanosomes 

 seen. Tendency 

 to clump 



30 „ 



»» 





» 



)> 



Motionless 



1 or 2 active 

 forms seen. Rest 

 motionless 



1 hour 





In a dilution experiment with lithium antimonyl tartrate made with the 

 blood of a Surra rat after a second recurrence, after treatment with antimony 

 (metal) and on first recurrence with lithium antimonyl tartrate, the 

 trypanosomes in vitro appeared to have a greater resistance to the dilute 

 drug than the stock strain. 



A comparison of the following table with the previous one will demonstrate 

 this :— 



Dilutions. 



Time. 



1—1000. 



1—5000. 





A number of active forms present 



1 min. 

 10 mins. 

 30 „ 











This bears out our experience that the recurrences become less and less 

 amenable to antimony as they increase in number. 



The following table shows the action of atoxyl and lithium antimonyl 

 tartrate compared in the above manner : — 



