The smaller respiration apparatus of Pettenkoffer and Voit. Air enters the cage, A, at the upper left-hand corner. It is drawn out through openings in the tube B (so spaced as to insure thorough diffusion) through the tube, C, and the large H2O flask, where it is saturated with moisture, to the gas meter, D, where it is measured. The meter is driven by a water wheel, W, rotated at a uniform rate of speed by a constant head of water pressure, V. At E a side tube leads off from C conveying a sample of cage air for analysis. This air is drawn through a mercury valve, F, by means of the mercury pump, G. The latter is operated by the mechanism, X, Y, connected with the water wheel. From the valve F, this air passes through two H2SO, flasks and is then saturated with moisture so as to prevent loss of water from the Ba(OH), tubes. Of course, the air, as it leaves the Ba(OH), tubes, is saturated with moisture, and is measured by the small gas meter, H, just as in the case of the large meter, while in this saturated condition. A duplicate sample is led off at the same time through another branch of the tube, E, and through another system of vessels to the gas meter at 3. Through the branches of the tube, L, duplicate samples of the air which enters the cage are drawn in the same manner to similar valves, and then through similar vessels and tubes to meters placed at 1 and 4. (Tigerstedt's "Human Physiology".) THE ELEMENTS OF THE SCIENCE OF NUTRITION BY GRAHAM LUSK, PH. D., SC. D., F.R.S. (EDIN.) PROFESSOR OF PHYSIOLOGY AT THE CORNELL UNIVERSITY MEDICAL COLLEGE, SECOND EDITION, REVISED AND PHILADELPHIA AND LONDON W. B. SAUNDERS COMPANY 1909 Set up, electrotyped, printed and copyrighted September, 1906. Revised, Copyright, 1909, by W. B. Saunders Company. PRINTED IN AMERICA PRESS OF W. B. SAUNDERS COMPANY PHILADELPHIA |