TREATMENT OF TRYPANOSOMIASIS. 35 



The experiments of Series II indicate that the majority of the monkeys 

 treated with a dose of 0.08 gram per kilo will recover from trypanoso- 

 miasis, and, hence, the results obtained in Series I are confirmed. 



Series III. — The strain of surra employed in these investigations 

 was obtained from one of the horses on the Government stock farm at 

 Alabang where an epidemic of surra existed. Prom this horse the 

 strain was inoculated into a monkey. On September 9, 1909, 1 cubic 

 centimeter of the monkey's blood containing numerous trypanosomata 

 was added to 200 cubic centimeters of salt solution and H cubic centi- 

 meters of the suspension injected into each of 21 monkeys. 



Two of the untreated monkeys which served as controls died twenty- 

 two and twenty-three days, respectively, after the inoculation with 

 surra blood. A third monkey, No. 4630, was already moribund from 

 the infection at the time when the treatment of the other monkeys was 

 begun, and may therefore be regarded as a third untreated control. 



On September 14 trypanosomata were found in the blood of all the 

 monkeys of the series and treatment in doses of 0.1 to 0.26 gram per 

 kilo, of arsenophenylglycin was administered. None of these monkeys 

 have suffered a relapse and none have received a second treatment. 

 Eleven of them are alive and free from trypanosomata, after five and 

 two-thirds months. 



One (monkey No. 4616) was free from parasites for four and one- 

 half months and was then lost. Monkey No. 4625 died after three 

 months, its blood being free from parasites just before death. The other 

 animals of the series which died, apparently succumbed from the effects 

 of the drug. 



Series III demonstrates clearly that monkeys receiving single doses 

 of from 0.1 to 0.26 gram of arsenophenylglycin are permanently cured 

 of the disease, although some of them will die from the toxic effects of 

 the drug. Doses of from 0.1 to 0.2, inclusive, effect permanent cures 

 with only a small percentage of deaths. 



Series IV. — On September 22, 1909, the monkeys of Series IV were 

 inoculated with the blood of monkey No. 4632, which constituted a 

 control animal employed in Series III. Trypanosomata were found 

 present in the blood of these animals on September 27 and all but one, 

 which served as a control, were treated on September 28. The untreated 

 control monkey died from the surra infection seventeen days after 

 inoculation. 



Very large doses of the drug (0.26 to 0.36) were administered and 

 the three animals which survived these doses have remained free from 

 parasites for six months. 



Summarizing these results, it may be stated that not a single monkey 

 which received 0.1 gram of arsenophenylglycin per kilo or a greater 

 amount has shown trypanosomata in the blood twenty-four hours after 



