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



Further experiments made with Rats treated with Antimony in order to find 

 out in what Organs the Trypanosomes are latent. 



Following on the experiments made on rats treated with sodium antimonyl 

 tartrate, with the view of finding out where the trypanosomes are latent, and 

 recorded in the last paper,* a further series of experiments has been made 

 on rats inoculated with Surra, which is more amenable to treatment with 

 antimony than the Nagana used in the former series, and completely 

 treated (that is, given a curative series of doses) with lithium antimonyl 

 tartrate : this, as stated in the paper referred to, appears to be the most 

 active of this variety of salt. 



Seven rats were treated with four doses of 5 minims of a 1 per cent, 

 solution of lithium antimonyl tartrate, and they were killed in succession, 

 one on the 6th, 7th, 10th, 14th, 16th, 22nd, and 30th days after the last 

 dose. The livers and bone-marrows were made into an emulsion with the 

 minimum quantity of 0'89 per cent, salt solution, and 1 c.c. of the emulsions 

 of these organs and 1 c.c. of heart's blood was injected separately into other 

 rats. The results were entirely negative. Microscopic preparations were 

 made of the material injected and no organisms were seen, and none of the 

 sub-inoculations gave a positive result. 



Experiments made in order to see if any Protection was afforded by Initial 

 Treatment with Antimony. 



A series of six rats was treated with four doses of 5 minims of a 

 1 per cent, solution of lithium antimonyl tartrate, one dose every other day 

 in the same manner as when given for curative purposes. They were then 

 inoculated with Surra, one on the first day after the completion of the treat- 

 ment, and one on the 2nd, 4th, 5th, 9th, and 10th days after. They all died 

 on the 5th or 6th days after inoculation, just as untreated rats would have 

 done, so that antimony in this very soluble form is of no protective use in 

 rats, owing most probably to its rapid elimination. 



The blood of an uninfected rat treated as above has also been used in the 

 in vitro experiments recorded below. 



Bats treated with Sodium Antimony Lactate and with Antimony Sodium 



Calcium Lactate. 



Through the kindness of Messrs. von Heyden we have been enabled to 

 make some experiments with the above compounds. The sodium antimony 

 lactate contains 26 per cent, of antimony, and the antimony sodium calcium 

 * ' Eoy. Soc. Proc.,' B, vol. 80, p. 487. 



