To the Editor:—
Drs. Edward J. Stieglitz and Alva A. Knight in their preliminary report on "Sodium Ferrocyanide as a Clinical Test of Glomerular Efficiency" (The Journal, Dec. 8, 1934, p. 1760) gave no credit to the originators of this test when "presenting a new procedure."Erich Leschke presented it (Histochemische Untersuchungen über die funktion der Niere und Leber, in the Verhandlungen der deutschen Kongresses für innere Medizin, Wiesbaden, 1914, p. 635, with Bunge). The first time sodium ferrocyanide as a renal functional test was spoken about was by Biberfeld and Basler.Alois Wolff in reviving this test (Die geschlossene, kavernose Nierentuberkulose, in the Zeitschrift für urologische Chirurgie6:364, 1921) came to the conclusion that if the kidney function is sufficiently impaired the ferrocyanide salts are still traceable when neither indigocarmine nor phenolsulphonphthalein are eliminated any more.