The Cambridge History of English and American Literature in 18 Volumes (1907–21).
Volume XIV. The Victorian Age, Part Two.

VIII. The Literature of Science

§ 30. Stephen Hales

British physiology, which had started magnificently with Harvey, and had continued under Mayow, de Mayerne and others, was carried forward by Stephen Hales, at one time fellow of Corpus Christi college, Cambridge, and for years perpetual curate at Teddington. He was a born experimenter, and, as a student, worked in the “elaboratory of Trinity College,” which had been established under the rule of Bentley, ever anxious to make his college the leader in every kind of learning. Sachs has pointed out that, during the eighteenth century, the study of the anatomy of plants made but little progress; but there was a very real advance in our knowledge of plant physiology. This, in the main, was due to Hales; he investigated the rate of transpiration and held views as to the force causing the ascent of sap which have recently come to their own; he recognised that the air might be a source of food for the plant and “connected the assimilative function of leaves with the action of light,” though he failed to find the mode of the interaction. He worked much on gases, and paved the way for Priestley and others by devising methods of collecting them over water. Hales, this “Poor, good, primitive creature,” as HOrace Walpole called him, was not less remarkable as an investigator of animal physiology, and was the first to measure the blood-pressure, and the rate of flow in the capillaries. Sir Francis Darwin states:

  • In first opening the way to a correct appreciation of blood-pressure Hales’ work may rank second in importance to Harvey’s in founding the modern science of physiology.
  • He was, further, a man of “many inventions,” especially in the fields of ventilation and hygiene.