It is not my place to speak of Hales' work in animal physiology, nor of those researches bearing on the welfare of the human race which occupied his later years. Thus he wrote against the habit of drinking spirits, and made experiments on ventilation by which he benefited both English and French prisons, and even the House of Commons; then too he was occupied in attempts to improve the method of distilling potable water at sea, and of preserving meat and biscuit on long voyages[57].
Plate IX
Plate 18 from Hales's Vegetable Staticks
Fig. 40. Instrument devised by Hales to make prick-marks on a young shoot of Vine (Fig. 41); the distribution of stretching after growth is shown in Fig. 42. The use of a similar instrument for marking surfaces is shown in Figs. 43 and 44
We are concerned with him simply as a vegetable physiologist and in that character his fame is imperishable. Of the book which I have been using as my text, namely, Vegetable Staticks, Sachs says: "It was the first comprehensive work the world had seen which was devoted to the nutrition of plants and the movement of their sap.... Hales had the art of making plants reveal themselves. By experiments carefully planned and cunningly carried out he forced them to betray the energies hidden in their apparently inactive bodies[58]." These words, spoken by a great physiologist of our day, form a fitting tribute to one who is justly described as the father of physiology.
FOOTNOTES:
[17] In 1699 Newton was made master of the Mint and appointed Whiston his Deputy in the Lucasian Professorship, an office he finally resigned in 1703 (Brewster's Life of Newton, 1831, p. 249).