294 NATURAL SCIENCE. Oct., 



being made to establish in England an Institution for this purpose 

 not inferior in efficiency to those of other countries, may have the 

 sympathy of all present ? " 



Physiology not Physics. 



The final expression of Dr. Sanderson's opinion of the nature 

 of physiological processes is of great interest. There is a certain 

 "specific energy of cells" that neither physics nor chemistry can 

 explain ; and physiology can never become a mere branch of applied 

 physics or chemistry. Nevertheless, there are parts of physiology 

 wherein the principles of these sciences may be applied directly. 

 " Thus, in the beginning of the century, Young applied his investiga- 

 tions as to the movements of liquids in a system of elastic tubes, 

 directly to the phenomena of the circulation ; and a century before 

 Borelli successfully examined the mechanism of locomotion and the 

 action of muscles, without reference to any excepting mechanical 

 principles. Similarly, the foundation of our present knowledge of 

 the process of nutrition was laid in the researches of Bidder and 

 Schmidt, in 1851, by determinations of the weight and composi- 

 tion of the body, the daily gain of weight by food or oxygen, the 

 daily loss by the respiratory and other discharges, all of which could 

 be accomplished by chemical means. But in by far the greater number 

 of physiological investigations, both methods (the physical or chemical 

 and the physiological) must be brought to bear on the same question 

 — to co-operate for the elucidation of the same problem. In the 

 researches, for example, which during several years have occupied 

 Professor Bohr, of Copenhagen, relating to the exchange of gases in 

 respiration, he has shown that factors purely physical — namely, the 

 partial pressures of oxygen and carbon dioxide in the blood which 

 flows through the pulmonary capillaries — are, so to speak, interfered 

 with in their action by the ' specific energy ' of the pulmonary tissue, 

 in such a way as to render this fundamental process, which, since 

 Lavoisier, has justly been regarded as one of the most important in 

 physiology, much more complicated than we for a long time supposed 

 it to be. In like manner Heidenhain has proved that the process of 

 lymphatic absorption, which before we regarded as dependent on 

 purely mechanical causes — i.e., differences of pressure — is in great 

 measure due to the specific energy of cells, and that in various 

 processes of secretion the principal part is not, as we were inclined 

 not many years ago to believe, attributable to liquid diffusion, but to 

 the same agency. I wish that there had been time to have told you 

 something of the discoveries which have been made in this particular 

 field by Mr. Langley, who has made the subject of ' specific energy ' 

 of secreting-cells his own. It is in investigations of this kind, of 

 which any number of examples could be given, in which vital 

 reactions mix themselves up with physical and chemical ones so 

 intimately that it is difficult to draw the line between them, that the 



