74 ELSDON: NOTE ON HUMAN MILK NOTE ON HUMAN MILK. BY G. D. ELSDON, B.Sc., F.I.C. (Read at the Meeting, February 2, 1916.) Two samples of human milk (taken from the same source on two successive days) recently examined by the writer, had the following composition, the lactose being determined by difference : Fat ... ... ... ... 4.0 3 *5 Lactose ... ... ... ... 7.5 7.4 Proteins ... ... ... ...1.5 1.4 Ash ... ... ... ... 0.2 0.2 Per cent,. Pcr ceii t. The mixed fat of samples taken on several successive days had the following characteristics ; Refractive index 40" C. ... ... ... ... 1.4568 Zeiss butyro refrrcctometer 40" C. ... ... ... 46.3 Reiohert-Meissl value (5 grms.) ... ... ... 2.0 Polenske value ... ... ... ... ... 2.2 Kirschner value ... ... ... ... 1.9 The mixed fat from four other samples of different origin had a refractive index at 40" C.of 1.4576, and gave a butyro refractometer reading at 40' C. of 47.5. I n the years 1910 and 1911, 146 samples of human milk were examined in the City of Birmingham Analytical Department in connection with an investigation on nutrition which was being carried out by the Medical Officer of Health ; the samples were obtained from twenty different mothers over a period of about ten montbs. Many of the analyses were carried out by the writer, and the following figures are now published by the courtesy of Mr.J. F. Liverseege, the Birmingham City Analyst ; those analyses not made by the writer were made by Mr. Norman Evers. Sixty-seven samples were completely analysed with the following average results, the lactose being determined by difference. Solids. Fat. Proteins. Ash. Lactose. Total Solicls-not- Fat. Average per cent. ... 11.7 8.59 3-11 1.19 0.21 7.18 Maximum ,, ... 14.6 9.1 5.9 1.8 0-3 7.6 Minimum ,, ... 9.6 8.0 1.1 0.7 0.2 6.6 Seventy-nine samples were partially analysed with the following average results : Total Solids. Solids-not-Fat. Fat. Average per cent. ... 11.78 8.50 3.28 Maximum ,, ... 14.3 9.4 5.7 Minimum ,, ... 9.4 7.9 0-7 MUXICIPAL CHEMICAL LABORATOBY, SALFORD.