Note 31 — I. EXPERIMENTS WITH PROFESSIONAL MEN.

All figures for nitrogen throughout the book, whether referring to food, urine, or fæces, were obtained by exact chemical analysis, using the Kjeldahl-Gunning method.

Uric acid was determined by the method of Folin, i. e., precipitation of the urine with ammonium sulphate, etc., and titration with potassium permanganate.

Phosphoric acid was estimated by titration with a standard uranium solution, using potassium ferrocyanide as an indicator.

At times, as will be seen from the tables, nitrogen, uric acid, etc., were not determined in each day’s urine. In such cases, an aliquot part of each twenty-four hours’ urine was taken and the analyses made with the mixed samples for the given period, the figures thus obtained showing the average daily composition for that period.