32 STRONG AND TEAGUE. 



Ill our preliminary experiments with this preparation, 53 monkeys 

 were employed. Out results were very unsatisfactory, for our animals 

 very frequently died, either from the toxic effects of the drug, or from 

 trypanosomiasis, due to the fact that sufficiently large doses of arseno- 

 phenylglycin to cure the infection had not been administered. Later we 

 learned that this first lot which we received was an inferior product in 

 comparison with the drug as prepared by Ehrlich at a later date. For 

 this reason the detailed experiments and the protocols of these 53 monkeys 

 are omitted in this paper. It is believed that their introduction would 

 only cause confusion, as the results obtained are now of little value as 

 compared with those derived from our later and most complete experi- 

 ments with arsenophenylglycin. Mention here of these preliminary ex- 

 periments is merely made in case that other observers have encountered 

 similar results with an inferior sample of the drug. A short time after 

 these first experiments were carried out. a second shipment of arseno- 

 phenylglycin was received and the fatal dose for monkeys accurately 

 determined with this preparation. 



The monkeys employed in these experiments, Cynomolgus philip- 

 pinensis Geoff., were in good condition, having been recently captured. 

 The results in determining the dosage are given in Table I, from which 

 it may be seen that the minimum lethal dose equals 0.22 to 0.26 gram 

 per kilo of body weight of animal. The drug was administered in 5 

 per cent solution, subcutaneously. No local reaction of any consequence 

 was noted following our injections into monkeys. In using the arseno- 

 phenjdglycin, the sealed tubes were opened, the drug dissolved at once 

 in distilled water and immediately injected. Those animals which died 

 with acute symptoms from an overdose of the drug usually lived only for 

 from two to ten days after the injection. Some of them suffered with 

 bloody diarrhoea before death. At autopsy, the liver and kidneys usually 

 showed marked fatty degeneration, the lesions present being similar to 

 those which have been regularly described in poisoning from atoxyl. 



Treatment. — After determining the most favorable dosage necessary 

 in monkeys, we proceeded to treat animals which had previously been in- 

 fected with the trypanosoma of surra. In every instance the parasites 

 were present in the blood of the animal at the time the treatment was 

 undertaken. 



Discussion of Table II. — Table II gives the results observed with four 

 series of monkeys, the individuals of a given series having been inoculated 

 with the same surra blood at the same time and treated at the same 

 interval after the infection. 



Sebies I contains 20 monkeys, 10 of which had been recently captured, 

 the others having been in captivity in the laboratory for variable periods 

 of time. Many of the latter had been used for other experiments and 

 were not in good condition at the time of the present inoculation. For 



