TREATMENT OE TRYPANOSOMIASIS. 25 



Acetylated atoxyl (arsacetin) was first prepared b.y Ehrlich and Bertheim, who 

 showed that it was much less toxic than atoxyl for several species of animals 

 and that it could be sterilized without decomposition. Browning believed that 

 animals could withstand ten times the amount of arsacetin as of atoxyl. He 

 also believed that the drug was much more effective than atoxyl in the treatment 

 of infected mice. The experiments by Breinl, however, seem to show that 

 arsacetin is less toxic for animals very susceptible to atoxyl, such as dogs, and 

 that proportionately it is not less toxic for horses and guinea pigs. TJhlenhuth 

 and Woithe confirmed the fact that arsacetin was less toxic for rats than atoxyl. 

 Browning and Wendelstadt, who employed the drug in the treatment of rats, 

 noticed marked tremor a long time after the injection of the drug, in the animals 

 which recovered. Wendelstadt concluded that while rats could be cured with 

 arsacetin. in the large doses required to produce a good result, unfavorable 

 symptoms usually appeared. Moore, Nierenstein and Todd found arsacetin supe- 

 rior to atoxyl. However, when used alone, the animals were not cured by this drug. 



The only difference from a chemical standpoint between arsacetin and atoxyl 

 consists in the partial acetylation of the amino group. Kopke has reported it 

 to be very probable that in the treatment of human trypanosomiasis one can 

 obtain with arsacetin the same therapeutic result as with atoxyl, perhaps with 

 less risk of poisoning. Eckard has employed tile drug in 134 cases of sleeping 

 sickness. Eighty-six of these were improved, but the cases had not been observed 

 for a sufficient length of time for the author to determine definitely the efficacy 

 of the drug. He considered the drug to be as valuable in the treatment of sleeping 

 sickness as atoxyl. 



Apparently, no reports of the use of this drug in the treatment of the 

 larger domestic animals have been published. The consensus of opinion 

 seems to be that it possesses about the same, or a little better therapeutic 

 value than at 0x3d. 



Experiments with other derivatives of atoxyl, such as salicyl atoxyl, 

 forniyl atoxyl, sodium p-hydroxyphenyl arsenate, disodium azobenzene 

 4-arsenate, disodium 4-oxyazobenzene 4-arsenate, tetrasodium phenazine 

 4-arsenate, sodium di-/j-acetyl aminophenylarsenate (Breinl and Nie- 

 renstein) and with substances closely allied, but having instead of an 

 aniline a toluidin nucleus, for example, orsudan and its derivatives, have 

 also been undertaken, but with no more favorable results. 



This concludes the list of compounds of arsenic which have already 

 been extensively employed. The use of arsenophenylglycin, a new prep- 

 aration, will be considered when our experiments are discussed. 



IV. TREATMENT WITH COMPOUNDS OF ANTIMONY. 



Plimmer and Thomson suggested the use of antimony, an element 

 chemically closely allied to arsenic, in the treatment of experimental 

 trypanosomiasis in 1907. 



They employed the sodium potassium and lithium salts of antimonyl tartrate, 

 of which the sodium antimonyl tartrate proved to be the most efficacious. It 

 quickly caused the disappearance of the parasites from the blood after injection. 



Of 39 rats injected and treated with the drug, the majority were living 

 fifty-two days later. This interval is obviously too short to enable a judgment 



