The clinical use of diuretics has fortunately been accompanied by careful studies of their mode of action. Exact agreement is not yet in evidence, but enough is now known to increase materially confidence in therapeutic administration.
Two groups of diuretics —the xanthine derivatives and the mercurials — have received most clinical and experimental attention. The physiologist is interested primarily in the place and mechanism of action, the clinician in the indications and contraindications for the use of diuretics. Schmitz in 1932, after reviewing the work done on this subject up to that time, concluded that Rehberg's method of calculating the amount of filtration occurring in the glomeruli and the amount of reabsorption taking place in the tubules was satisfactory for comparing the diuretic action of theophylline ethylenediamine and salyrgan in the dog. During theophylline ethylenediamine diuresis the calculated amount of glomerular filtration was consistently increased, while tubular reabsorption showed