505 



A Preliminary Summary of the Results of the Experimental 



Treatment of Trypanosomiasis in Rats. 



By H. G. Plimmer, F.L.S., and J. D. Thomson, M.B., CM. 



(Communicated by Sir Eay Lankester, K.C.B., F.E.S. Eeceived July 20, 1907.) 



The experiments of which the following note is an abstract have been 

 undertaken under the direction of the Tropical Diseases Committee of the 

 Koyal Society. 



The strains of trypanosomes which have been used in these experiments 

 are a Nagana from the original strain brought to England, and a Surra from 

 Professor Lingard in India. The Nagana strain kills rats in an average time 

 of 5*5 days, and the Surra strain in 6*9 days. 



Ghinolin Compounds. 

 The knowledge of the action of quinine in malaria suggested the trial of 

 various chinolin compounds. As is well known, quinine itself has no 

 influence in trypanosomiasis. Cyanin was the substance first tried, as this 

 in extremely dilute solutions (1 — 10,000) is very poisonous to trypanosomes 

 outside the body. A series of .Nagana and Surra rats were given doses of 

 from J to 1 milligramme (which is a poisonous dose for small rats), but all of 

 these died about the same time as the controls, and in every case the 

 trypanosomes had increased in the usual manner, so that at death the blood 

 was as swarming with trypanosomes as if no treatment had been used. 

 Messrs. Bayer and Co., of Elberfeld, kindly placed at our disposal nine 

 chinolin and chinaldin compounds and six " cyanin farbstoffe," but none of 

 these produced any effect on the development or course of the diseases. 



Dichlorobenzidine + Acid H. 

 This substance, which was first used by Mcolle in trypanosomiasis of mice, 

 was found, when used both on mice and rats, to lengthen the course of the 

 diseases, but in no case was the extension of the course of the disease very 

 marked. Nagana mice, after one dose of 1 c.c. of a 1-per-cent. solution, lived 

 from 8 to 11 days, and Surra mice from 10 to 16 days, one living as long as 

 29 days ; in Nagana rats the disease was prolonged to an average time of 

 14 days, and in Surra to an average of 16 days. In all the animals treated 

 with this substance the spleen and liver were very much enlarged, and living 

 trypanosomes were found post mortem, showing that the substance had not 

 practically influenced the pathological processes. In no case was the 

 substance completely absorbed. 



