Each cell in the body takes the fuel which it needs for its activities, and combines it with the oxygen brought by the red corpuscles; and when the task of power-production has been achieved, the cell puts back into the blood-stream, not merely the carbon dioxide, but many complex chemical products-ammonia, uric acid, and the "fatigue poisons," indol, phenol and skatol.
"The Book of Life: Vol. I Mind and Body; Vol. II Love and Society"
Upton Sinclair
Several glass plates are prepared, by spreading on each a solution of gelatine of different concentration, to which a few drops of phenol phthalein have been added.
"The Mechanism of Life"
Stéphane Leduc
It is, went on Kennedy, as the full horror of the thing sank into our minds, the indol-and phenol-producing bacteria which are the undesirable citizens of the body, while the lactic-acid producing germs check the production of indol and phenol.
"The Dream Doctor"
Arthur B. Reeve