The purpose of the present investigation was to compare the effectiveness of neoarsphenamine and mapharsen administered by the continuous intravenous drip method of Chargin, Leifer and Hyman,1 once a day for five days in succession, with that of the drugs administered in single doses by intravenous injection with the syringe in the usual manner, in the treatment of early or acute syphilis of rabbits.
Adult rabbits were inoculated intratesticularly with the Nichols-Hough strain of Spirochaeta pallida, and treatment was instituted on the development of acute syphilomas showing numerous actively motile spirochetes on dark field examination.
Both compounds were administered in 5 per cent solutions of dextrose. With the continuous drip method each dose was prepared in a total of 80 cc. and given intravenously at the rate of 15 to 30 drops per minute, which required about four hours; one treatment was given on each of five successive days.