paper he discussed the results whim had been obtained from his studies
of the adrenal gland. The results he obtained are probably best told in
his own words: -"To see whether the adrenal cortex contains any such
reducing agent the gland was cut with a knife into halves-which were
immersed in a 0. 4% AgN0 solution. In a few minutes the cortical part 3
was seen to darken through the deposition of reduced metallic silver. In
a quarter of an hour the cut surface of the cortex turned completely
black while the medulla remained largely uncoloured. The black
colouration ends towards the medulla with a sharp margin, which
corresponds to the anatomical margin between the medulla and cortex.
Like the medulla, other organs, such as brain, liver and muscle remain
practically uncoloured. " When the gland was immersed in a mixture of
potassium iodate and acetic acid-a reagent for adrenalin, the medulla
became violet in colour and the cortex remained colourless.
SZENT-GYÖRGYI therefore came to the conclusion that: -"The adrenal
cortex therefore, contains some specific highly reducing agent which can
be no arte fact, since its action is produced in the almost fresh
material. " Methyl alcohol extracts of the cortex reduced neutral silver
nitrate almost instantaneously and when the portions of the interrenal
glands of Elasmobranm fishes were treated with silver nitrate solutions
they too went black-so that it appeared that this highly reducing factor
was a funda- mental constituent of adrenal tissue.