the topics discussed. The presidency of these bodies is held as an eminent honor among men of science, to be filled but once in a lifetime, and then by gentlemen of the highest scientific ability. These addresses are read with interest throughout the scientific world, and they naturally call forth the best exertion that their authors are capable of making. In the present case the speakers have taken up the subjects to which their lives have been devoted, and upon which they are prepared to discourse with authority. This, however, is more especially the case with Prof. Gray. An accomplished botanist, who is, moreover, much of a philosopher, and can work at causes and effects in Nature as well as at identifying and labelling specimens, he has grappled with the profoundest question in his own domain, the origin, descent, and modifications of vegetable forms on this continent, and has handled it with a clearness, originality, and richness of illustration, which cannot fail to increase his already high reputation. Dr. Carpenter has won his best fame in the field of physiology, although cultivating successfully various branches of natural history. As is shown in the biographical notice which we publish, he has paid special attention to the physiology of the nervous system, and has worked out a mental philosophy on the basis of cerebral physiology. One of the doctrines to winch he has paid much attention, and which he claims to have developed and extended so as to make it his own, was set forth by him in the lecture which we published last month, on the "Unconscious Action of the Brain." But while Dr. Carpenter has been an assiduous student of mind from this point of view, and is entitled to speak with authority upon the questions it involves, in the present address he has gone quite beyond this subject, and plunged into the utmost intricacies of metaphysics. His address contains much that is instructive in regard to the methods of science in interpreting Nature; and in addition to this he makes a vigorous attack on the new philosophical school that has lately grown up into strength within the circles of science. His argument is generally regarded as a protest and a reaction against recent and as many think mischievous scientific tendencies.
It is curious to note the course of thought for the past few years, in these two Associations, dedicated to the "advancement" of ideas, as that course is evinced by the leanings of the presidential speeches. Those of the American presidents have been cautious and timid, and they seem to have hesitated about committing themselves to "advanced" views. Prof. Gray is the first who has ventured officially to avow Darwinian doctrines. On the other hand, the later presidents of the British Association, Grove, Hooker, and Huxley, have been representatives of these doctrines. This year, however, the tendencies in both bodies would seem to be reversed—the American president breaking away from the conservatism of his predecessors, and the British president putting on the breaks to check the radical movement in his own body.
Yet Dr. Carpenter has neither arrayed himself against the doctrine of "Darwinism," nor is his scientific orthodoxy by any means above suspicion. He was among the first to assert and elaborate the great doctrine of the correlation of physical and vital forces, and, in the fifth edition of his "Principles of Physiology," he carried out the argument by including the mental forces in the correlated group. This doctrine was denounced as heretical and dangerous by Dr. Barnard, in his address before the American Association at Chicago, and, if we remember rightly, so great was the scare in England at the position taken by Carpenter, which was reprobated as rank ma-
