Note on the stereophotochromoscope : a new optical instrument / by David Fraser Harris.

  • Fraser-Harris, David Fraser, 1867-1937.
Date:
[1895]
Catalogue details

Licence: Public Domain Mark

Credit: Note on the stereophotochromoscope : a new optical instrument / by David Fraser Harris. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    NOTE ON THE EEDUCING-POWER OF THE TISSUES. By David Fkaser Hakeis, M.B. c It is a fundamental conception in modern physiology that the tissues have an avidity for oxygen,—that internal or tissue- respiration is the process whereby oxygen is abstracted from the blood. This was lately demonstrated to myself accidentally when injecting an animal for histological purposes with the Berlin- blue and gelatine mixture. The instant the animal's heart ceased beating, it was bled from the apex of the right ventricle, and simultaneously the Berlin-blue mjection through the aorta proceeded with. After the body had cooled and the organs were cut open, I was dis- appointed with the appearance of several of them, liver and kidneys especially,—thinking them uninjected, so pale did they appear. Parts seemed not coloured at all, others of the palest green; while in some of the large divisions of the portal vein in the liver, the gelatine mass seemed absolutely colourless. Every part of the lung was of the deepest blue. Glancing at the little bits of liver and kidney ten minutes afterwards, I noticed they were distinctly deeper coloured; three minutes afterwards the deepening was undoubted; next morning (they had lain overnight in 10 per cent, formol), one would have said that parts were now well injected which the day before were colourless and apparently filled with gelatine only. This was an undoubted case of de-oxidation by the living tissues, for the injection had been made so rapidly that both kidney and liver were practically ' alive,' and their avidity for oxygen uncompromised. Berlin-blue or Prussian-blue (a 2 per cent, solution) is ferric ferrocyanide—a Uue salt; on de-oxida- tion it was reduced to a ferrous salt of light green colour; further de-oxidised (as in the liver) it was bleached to a colour- less salt, or the chromogen of Prussian-blue. ?