344 POPULAR SCIENCE MONTHLY. 



ear were also made in Ludwig's laboratory. In fact, by the establish- 

 ment of the histological department of his institute, he exercised a 

 marked influence on the development of minute anatomy. 



If Ludwig's experimental methods were characterized from the 

 beginning by their extraordinary precision, this quality was simply 

 the result of the serious cast of his whole character. At whatever 

 time one might happen to enter his laboratory, one always received 

 the impression that it had just been put in order, and that every 

 article was in its proper place. 



The numerous investigations which Ludwig caused to be made 

 on the most important parts of the body of course furthered the 

 advance of medical science. The results of his researches benefited 

 theoretical medicine, and his fully developed methods were of great 

 advantage in experimental pathology and in clinical observations. 

 Among Ludwig's pupils were a large number of eminent clinicians. 

 Ludwig himself, however, always attached great importance to his 

 relations to medicine and the practical significance of physiology. 

 " Guiding the course of human life according to the dictates of 

 human wisdom " is what in his great work on physiology he gives 

 as his conception of the true aim of a physician, and later he several 

 times expressed the same idea in somewhat different words. 



It would be extremely interesting to follow more closely the in- 

 fluences that caused Ludwig to take up the physical side of physiology. 

 This is now no easy matter to determine, and even inquiries that I 

 have made among his surviving friends and pupils have given me no 

 definite opinion. An accurate manner of thinking and great mental 

 independence were always peculiar to Ludwig, and they were per- 

 haps the qualities that caused him to turn aside from all beaten paths. 

 As a student, this feeling of independence brought him into conflict 

 with the laws of discipline in his university, and resulted in a tem- 

 porary suspension of his studies there. On his return to Marburg 

 he seems to have finally decided on making physiology his profession, 

 and it was then that he entered Bunsen's laboratory. In the 

 analyses that were undertaken there he probably had his first oppor- 

 tunity of becoming familiar with the more accurate physical meth- 

 ods. There he also had intercourse with other young physicists, 

 among whom was Reiset. Bunsen's strict training must, indeed, 

 have been a strong contrast to the unsystematic routine of the Bam- 

 berg surgeon with whom Ludwig had spent his time of suspension. 

 From 1842 (the year of the inaugural thesis) onward he worked 

 on the problems of physical physiology with his friends and pupils.* 



* Among the standard works which he recommended to them at that time were the 

 writings of the Weber brothers (Die Wellenlehre, 1825 ; the treatises on the pulse, absorp- 

 tion, auditory and cutaneous sensation, 1834; and the locomotive organs, 1834), Poiseuille's 



