1276 



THE AFRICAN TRYPANOSOMIASES 



tions of Nierenstein, it is not the arsenic in these compounds which is to he 

 looked upon as the effective agent, but the amido-group, which may possibly 

 be the effective agent in trypan red, afridol blue, afridol violet, and para- 

 fuchsin, which do not contain arsenic, but possess amido-groups, and affect 

 trypanosomes in a similar manner to atoxyl. According to Ehrlich, Leva- 

 diti, and Yamanouchi, atoxyl undergoes a reduction in the animal tissues, 

 Ehrlich has prepared two derivatives of atoxyl, one of which, already men- 

 tioned (arseno-phenylglycin), is very effective in mice on atoxyl-resistant 

 trypanosomes. Levaditi and Yamanouchi have also prepared an active 

 derivative of atoxyl, which they call trypanotoxyl. Nierenstein thinks that 

 atoxyl is oxydized in the tissues, and it is only in the nascent state that it 

 becomes efficacious. 



Soamin. — Owing to the fact that large doses of atoxyl lead to such un- 

 pleasant results as optic atrophy, gastro-intestinal inflammation, and peri- 

 pheral neuritis, other arsenical preparations have been recommended; and 

 the firm Burroughs and Wellcome has introduced, under the trade name of 

 soamin, a preparation somewhat similar to atoxyl, but said to be less poisonous. 

 It is given in the same doses as atoxyl, but the therapeutic results do not 

 appear to have been very successful. Soamin, according to the published 

 formula, is C2H4NH2AsO(OH) (ONa)5H20. 



Arseno-phenylglycin.— 'EhrMch. has prepared a derivative of atoxyl, called 

 afseno-phenylglycin, whichis from two to four timtes less toxic than atoxyl itself. 



This preparation has been tried by Ehrlich, Mesnil, Kerandel, and others 

 upon lower animals experimentally infected with C. castellanii, and has 

 been found to be very effective, being also a prophylactic. It has been used 

 in man by Kleine in the same doses as atoxyl, but has novV been abandoned. 



Liquor Arsenicalis. — When for special reasons it is impossible to carry out 

 the treatment by injections, arsenic may be given by the mouth in the form 

 of Fowler's solution, which must be given, well diluted in water or milk, in 

 5-minim doses, and graduafly increased to 15-minim doses. 



Loffler and Riih's neutral solution of arsenious acid (i c.c. of which contains 

 I centigramme of arsenious acid) may be given in doses of 2 c.c. daily for three 

 days, and then continued in doses of i c.c. per diem for several weeks, after 

 which it must be temporarily discontinued, but must after a time be restarted, 

 and in this manner continued for months, provided no ill-effects are produced. 



Salvarsan and Neosalvarsan.- — Their action is less efficacious than atoxyl. 



Atoxylate of Mercury.- — This preparation, introduced by Uhlenhuth, has 

 given less satisfactory results than atoxyl. 



Quinine Derivates.—M.oxgenroth. and Halberstaedter have shown that 

 some quinine derivatives, such as hydroquinin, have a preventive and curative 

 effect in certain experimental trypanosomiases. 



Ipecacuanha Derivates. — The emetine salts might be studied in regard to 

 their possible action on trypanosomes. 



Anarcotine. — The use of this opium alkaloid has been suggested by Johnson. 



Combined Therapy.- — -As the result of the important observations 

 of Ehrhch on the phenomenon of chemio-resistancy , which may 

 be acquired by trypanosomes after a long use of the same drug, 

 numerous combined treatments have been suggested. Of these, 

 the most important are: — fi) antimony and atoxyl; (2) mercury 

 and atoxyl; (3) orpiment and atoxyl; (4) various dyes and atoxyl. 



Antimony and Atoxyl Treatment . — Antimony salts, as well as phosphorus, 

 were first suggested by Mesnil as likely to be of use in trypanosomiasis. To 

 Plimmer and Thomas belongs the credit of having experimentally shown the 

 powerful trypanocide action of antimony. In man the subcutaneous or intra- 

 muscular injections of solutions of the various salts of antimony (sodo-tartrate 

 of antimony, sulphide of antimony and soda, etc.) are very painful. Plimmer 

 therefore suggests oil emulsions, Manson gives the drug by the mouth 

 or by the rectum, and other authors by intravenous injection. Daniels and 



