have been materially advanced; but, by his untimely death, the work devolved upon our Harvey, and he had to labour all but destitute of assistance from collateral science.
If, on reviewing the relations which general science bore to physiology in Harvey's time, we contrast it with our own, how great we find the contrast. Then there was but one object, but one method, and but one chief worker the indefatigable anatomising, the tracing of the intricate system of the vessels, the ecstatic contemplation of the wonderful contrivance of the valves, the close and accurate process of inductive reasoning―these were all his own; but, whilst pushing onwards to his great victory, he was checked in his advance by want of aid from collateral science. Even the mode of depuration of the blood in its passage through the lungs. could not but remain to him a mystery, because chemistry had to start to life before that process could be understood. Now, our fellow-workers are innumerable; and every succeeding year brings with it speculations founded on treasures of new facts which we
