1. Solar spectrum with Fraunhofer lines. 2. Absorption spectrum of a concentrated solution of oxyhæmoglobin; all the light is absorbed except in the red and orange. 3. Absorption spectrum of a less concentrated solution of oxyhæmoglobin. 4. Absorption spectrum of a dilute solution of oxyhæmoglobin, showing the two characteristic bands. 5. Absorption spectrum of a very dilute solution of oxyhæmoglobin, showing only the a-band. 6. Absorption spectrum of a dilute solution of reduced hæmoglobin, showing the characteristic single band (to be compared with spectrum 4). 7. Absorption spectrum of a dilute solution of carbon-monoxidehæmoglobin (to be compared with spectrum 4). 8. Absorption spectrum of methæmoglobin. 9. Absorption spectrum of acid hæmatin (alcoholic solution). 10. Absorption spectrum of alkaline hæmatin (alcoholic solution) (modified from MacMunn, The Spectroscope in Medicine).

OF

PHYSIOLOGY

HENRY P. BOWDITCH, M. D.
JOHN G. CURTIS, M. D.

HENRY H. DONALDSON, PH.D.
W. H. HOWELL, PH. D., M.D.

FREDERIC S. LEE, PH.D.

BY

WARREN P. LOMBARD, M.D.

GRAHAM LUSK, PH. D., F. R.S. (EDIN.)

W. T. PORTER, M.D.

EDWARD T. REICHERT, M.D.

HENRY SEWALL, PH. D., M. D.

EDITED BY

WILLIAM H. HOWELL, PH.D., M.D.

Professor of Physiology in the Johns Hopkins University, Baltimore, Md.

SECOND EDITION, REVISED

VOL. I.

BLOOD, LYMPH, AND CIRCULATION; SECRETION, DIGESTION,
AND NUTRITION; RESPIRATION AND ANIMAL HEAT;
CHEMISTRY OF THE BODY

WILLIAM H. HOWELL, PH.D., M. D.

Professor of Physiology in the Johns Hopkins University, Baltimore, Md.

SECOND EDITION, REVISED

VOL. I.

BLOOD, LYMPH, AND CIRCULATION; SECRETION, DIGESTION,
AND NUTRITION; RESPIRATION AND ANIMAL HEAT;
CHEMISTRY OF THE BODY

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