To the Editor:—
In reply to this note we wish to state that the reference to Leschke was unknown to us and failure to mention his work of 1914 entirely unintentional. It should be pointed out that prior to the work of E. K. Marshall Jr. (Am. J. Physiol.94:1 [July] 1930), J. G. Edwards (Am. J. Physiol.95:493 [Nov.] 1930) and of Gersh and Stieglitz (Anat. Rec.58:349 [March] 1934) there was no convincing evidence that ferrocyanide salts were excreted solely through the renal glomeruli. The earlier experimental work of Biberfeld and of Basler is discussed in some detail in the paper by Gersh and Stieglitz, to which reference is made in our clinical report in The Journal. The clinical application of sodium ferrocyanide as a significant test of glomerular efficiency was dependent on the experimental proof of the route and method of its renal elimination.