Page:The Harveian oration - delivered at the Royal College of Physicians, October 18th, 1899 (IA b24975941).pdf/26

 search out the reason of this double circulation, but it was not until Priestly and Cavendish and Lavoisier had founded modern chemistry that the relationship of circulation to respiration was fully established. The necessity of fresh air and the quantity needed for the healthy working of the body are now commonplaces. The working classes of this country have shown themselves ready to sup- port politicians who have legislated for more light and air in the house and in the workshop, and some day they will recognise that this advance is really traceable to the quiet workers who have been engaged in searching out the secrets of Nature by way of experiment, among whom Harvey must ever stand pre-eminent.

The microscope has informed us of the various cellular elements which circulate with the blood, and we have learnt, and are still learning, to dif- ferentiate various forms of anæmia, to attribute to cach its true proximate cause, and to indicate the direction in which relief is to be found. The spectroscope, again, is informing us as to the in- fluence of inspired gases on the blood, and the precise dangers incurred by workers in noxious places. This knowledge has suggested preventive measures and measures of recovery, for which thanks are due to those who have been busy in searching out the secrets of Nature by way of experiment.

The great advance of the latter half of this