TREATMENT OF TRYPANOSOMIASIS. 37 



atively smaller number of the intestinal cells to take up the drug and the con- 

 sequent rapid poisoning of the animal if the attempt be made to give the relative 

 dose. The relatively small number of cells must first act upon the drug before 

 it can be turned out as a. trypanocide for the parasites. 



This hypothesis can hardly be considered tenable without further experimental 

 evidence. According to Moore's theory, the maximum dose is proportional not 

 to the body weight but to the "two-thirds power of the body weight. 



Following are the details of the earlier experiments carried on with 

 horses : 



Horse No. 1. — Native pony. No history as to length of time sick with surra. 

 Head droops and general appearance bad, respirations rapid. Slight oedema of 

 abdomen, mucous membranes of mouth and tongue pale. Examination of blood 

 on April 22 with one-twelfth oil immersion shows about 1 trypanosoma to a field. 



April 24, 4.8 grams of arsenophenylglycin dissolved in 100 cubic centi- 

 meters of distilled w,ater and injected subcutaneously. 



April 25, blood examination for trypanosomata negative. 



April 29, second injection of 6 grams of arsenophenylglycin subcutaneous!}'. 



May 3, third injection of 6 grams of the same drug intravenously. 



May 3, just before the injection of the drug, a monkey was inoculated with 

 20 cubic centimeters of the blood of the horse. Repeated examination of the 

 blood of the monkey never revealed trypanosomata. 



May 12, 10 cubic centimeters of horse's blood were injected subcutaneously into 

 a monkey. This monkey's blood was examined at intervals for a month with 

 negative results. However, the horse grew weaker, and was found dead on the 

 morning of May 18. 



Although we were unable to demonstrate any trypanosomata in the 

 blood of this animal, nevertheless, we believe that it succumbed from the 

 effects of surra. This was the first animal treated by us, and the doses 

 administered were evidently entirely too small for a cure to result. 



Eorse No. 2. — April 23. This animal was injected with 20 cubic centimeters 

 of the blood from horse No. 1 and which contained trypanosomata. The animal 

 died on May 11 of surra, being untreated and used for the purpose of keeping 

 at hand a virulent strain of trypanosoma for the infection of other animals. 



Horse No. 3. — Native horse; suffered with advanced symptoms of surra. 

 Marked oedema of the abdomen. Numerous trypanosomata present in the blood. 



April 24, 4.8 grams of arsenophenylglycin given subcutaneously. 



April 25, blood examination negative for parasites. Parasites did not re- 

 appear in the blood. 



April 29, 2 monkeys inoculated with the blood of this horse. Trypanosomata 

 did not subsequently develop in the blood of either of them. A second sub- 

 cutaneous injection of 4.5 grams of arsenophenylglycin was given and on May 3 

 another injection of 10 grams intravenously. On May 3, 1 monkey and May 7, 

 2 other monkeys were also inoculated with the blood of the horse. All these 

 animals remained negative for trypanosomata for over two months. The horse 

 died six days later (May 9), notwithstanding the fact that no trypanosomata 

 were found in its blood. Nevertheless, this animal probably died of surra infec- 

 tion and from the toxic effect of the last dose of the drug. 



Horse No. J h — Large native horse; received on April 29. Blood examination 

 positive for trypanosomata. No record of how long the animal has been sick 

 with surra. Temperature 40°. April 29, 8 grams of arsenophenylglycin in- 



