LUDWIG AND MODERN PHYSIOLOGY. 377 



we day by day or hour by hour disengage, whether in the form of heat 

 or external work. 



In the opening paragraph of this section it was observed that until 

 recently there had been no tendency to revive the vitalistic notion of 

 two generations ago. In introducing the words in italics I referred to 

 the existence at the present time in Germany of a sort of reaction, 

 which under the term " Neovitalismus " has attracted some attention — 

 so much indeed that at the Versammlung Deutscher Naturforscher at 

 Liibeck last September it was the subject of one of the general addresses. 

 The author of this address, Professor Eindfleisch, was, I believe, the 

 inventor of the word; but the origin of the movement is usually traced 

 to a work on physiological chemistry which an excellent translation by 

 the late Dr. Wooldridge has made familiar to English students. The 

 author of this work owes it to the language he employs in the intro- 

 duction on "Mechanism and vitalism" if his position has been misun- 

 derstood, for in that introduction he distinctly ranges himself on the 

 vitalistic side. As, however, his vitalism is of such a kind as not to 

 influence his method of dealing with actual problems, it is only in so 

 far of consequence as it may affect the reader. For my own part I feel 

 grateful to Professor Bange for having produced an interesting and 

 readable book on a dry subject, even though that interest may be partly 

 due to the introduction into the discussion of a question which, as he 

 presents it, is more speculative than scientific. 



As regards other physiological writers to whom vitalistic tendencies 

 have been attributed, it is to be observed that none of them has even 

 suggested that the doctrine of a "vital force" in its old sense should 

 be revived. Their contention amounts to little more than this, that in 

 certain recent instances improved methods of research appear to have 

 shown that processes at first regarded as entirely physical or chemical 

 do not conform so precisely as they were expected to do to chemical and 

 physical laws. As these instances are all essentially analogous, refer- 

 ence to one will serve to explain the bearing of the rest. 



Those who have any acquaintance with the structure of the animal 

 body will know that there exists in the higher animals, in addition to 

 the system of veins by which the blood is brought back from all parts 

 to the heart, another less considerable system of branched tubes, the 

 lymphatics, by which, if one may so express it, the leakage of the 

 blood vessels is collected. JSTow, without inquiring into the why of this 

 system, Ludwig and his pupils made and continued for many years 

 elaborate investigations which were for long the chief sources of our 

 knowledge, their general result being that the efficient cause of the 

 movement of the lymph, like that of the blood, was mechanical. At 

 the Berlin Congress in 1890 new observations by Professor Heidenhain, 

 of Breslau, made it appear that under certain conditions the process of 

 lymph formation does not go on in strict accordance with the physical 

 laws by which leakage through membranes is regulated, the experi- 



