CHEMICAL REMEDIES 291 



for the monkey; secondly, arsenophenylglycin (arsenophenyl 

 glycocollate of sodium), two to four times less toxic than 

 atoxyl and more active in killing the parasites and in pro- 

 phylactic power. Quite recently Strong and Teague in the 

 Philippines have been treating surra in horses with arseno- 

 phenylglycin on the scale of veterinary practice and not of 

 laboratory experiment, and have cured more than one-third of 

 the animals, besides checking the epidemic. In the series of 

 bodies studied by Ehrlich arsenophenylglycin had the number 

 418. Finally we reach the body numbered 606, the dioxy- 

 diamidoarsenobenzol (C 12 H 12 O 2 N 2 As 2 ), of which the hydro- 

 chloride is employed as the celebrated remedy termed " 606 " 

 or Salvarsan. 



5. The toxicity of these chemical remedies, the necessity of 

 treating relapses and the fear of rendering habituated to the 

 drug both the patient and the parasite, have suggested the 

 method of combined or more correctly alternated medication 

 (Laveran). The drugs associated may be of the same series 

 or of a different chemical series from the principal drug. In 

 spite of the good qualities of atoxyl arsenious acid still retains 

 the first place in the alternated treatment. 



Treatment of Sleeping-Sickness. From 1906 on- 

 wards atoxyl was the remedy most employed in the treatment 

 of sleeping-sickness. R. Koch during his sojourn in the Sese 

 Islands on the Victoria Nyanza, gave half a gram two days in 

 succession : in about eight hours the parasites disappeared 

 from the blood and from the swollen glands. They remained 

 absent for about ten days, when the injections were repeated 

 without inconvenience this double injection was continued 

 every six days for from four to six months. 



Koch observed further that on ceasing the injections the 

 parasites reappeared in the glands after a minimum period of 

 eleven days ; from the twenty-fifth day they could be found in 

 about 2 5 per cent, of the patients treated as above ; they then 

 disappeared and after the sixtieth day were not to be found 

 again. But the disappearance from the glands was not a final 

 cure : there were relapses. The prolonged treatment, how- 



u 2 



