The general plan of our intended research (which has been interrupted by Dr. Welker's removal from Philadelphia) was to study what changes, if any, could be found in the distribution of the urinary nitrogen after the use of certain typical diuretics, either in healthy persons or in nephritics. As examples of the purin group of diuretics we selected caffein and theophyllin. Our study of the former has been embodied in another article already published;1 the latter is considered in the present communication. A rather careful survey of the literature of theophyllin has failed to discover any previous study of the nitrogen partition under its influence, though Meinertz2 made carefully controlled estimations of the total nitrogen output.
Theophyllin (1,3-dimethyl-xanthin) was discovered in 1888 by Kossel3 in an alcoholic extract of tea leaves from which the greater part of the caffein had been removed. Fisher4 synthetized it