Directions for a practical course in chemical physiology / W. Cramer.

  • Cramer, William, 1878-1945.
Date:
1917
Catalogue details

Licence: In copyright

Credit: Directions for a practical course in chemical physiology / W. Cramer. Source: Wellcome Collection.

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    the inside of the bottle to the outer air. The pressure inside the apparatus is now the same as the pressure outside. Close the clip. The level of the water inside the burette is then at the same height as the level of the water in the jar. Read off the height in the burette with the water inside and outside at the same level. Now tilt the bottle so that the ferricyanide solution is upset, and shake gently as long as gas is evolved. When no more gas is evolved, replace the bottle in the water and wait five minutes. What reaction has taken place % Read the burette in the same way as before, i.e., with the water inside and outside at the same level. (Why is this necessary T) The difference in readings gives the amount of oxygen , held by 20 c.c. of defibrinated blood. Record the result. N.B.—In measuring gases, as in this experiment, the temperature must be kept as constant as possible. (Why ?) The apparatus should therefore be touched with the hands as little as possible, and no source of heat (gas flame, bunsen, etc.) must be near it. CHEMISTRY OF BLOOD PIGMENT. ABSORPTION SPECTRA OF HEMOGLOBIN AND ITS DERIVATIVES. Spectroscopic Examination of Blood Pigments. Solutions of haemoglobin and its derivatives give characteristic absorption spectra, which can be examined with a spectroscope. What is an absorption-spectrum ? Examine the spectroscopes provided. Note that the width of the slit at one end can be adjusted,1 and that the 1 In some spectroscopes the width of the slit is fixed.
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