34 o POPULAR SCIENCE MONTHLY. 



ences had been organized in Leipsic, and the ministry of instruction 

 had passed into other hands, Ludwig again confined himself to his 

 own more limited department. His activity in this field, however, 

 soon spread the fame of the Leipsic University throughout the world. 



When Ludwig first came to Leipsic he was in the prime of 

 mature manhood, and had already had twenty years of experience 

 in teaching. He had begun his academic career in Marburg, in 

 1841, where he had been associated with his friend Ludwig Fick as 

 demonstrator in anatomy. In 1849 he went from there to Zurich 

 as professor of anatomy and physiology, and in 1855 he was called 

 to Vienna to the medical military academy, the so-called Josephi- 

 num, as professor of physiology. 



In 1852, during his stay in Zurich, Ludwig published the first 

 volume of his text-book of Physiology, the second volume of which 

 appeared four years later, when he was in Vienna. Ludwig's 

 Physiology appeared like a meteor on the scientific horizon. It 

 attacked the scientific knowledge of the day, demolishing former 

 theories and conceptions with critical severity, and substituting new 

 ideas and modes of expression which to us, the physicians of that 

 time, seemed extraordinary enough. I well remember the sensa- 

 tions with which I, as an advanced student, on coming from one of 

 Johann Miiller's lectures, toiled through Ludwig's recently pub- 

 lished work. Much that it contained I could only master by an 

 effort, and much was actually repugnant to me, for it seemed to 

 me to shatter to atoms the most interesting chapters of physiology 

 as it had existed hitherto. And yet, in spite of all inward opposi- 

 tion, I could not resist the overwhelming influence of this powerful 

 book with its vast stores of information, and I had to acknowledge 

 more and more the force of its triumphant method of presentation. 



Wherein lay the great step in advance that Ludwig had taken 

 with his Physiology? Ludwig was a pronounced physical physiolo- 

 gist. A physical physiology had, however, existed long before his 

 time. During the preceding two centuries there had already been 

 schools of mechanical therapeutics in which classical works, as those 

 of Borelli on animal movement, of Hales on blood-pressure, had been 

 produced. Beginning in the second decade of this century, the Weber 

 brothers had proved themselves investigators of the first rank, and 

 their fundamental experiments on wave motion, the pulse, human 

 locomotion, on muscular contraction, etc., were founded on a strictly 

 physical basis. Other men of similar ideas, among them A. Volk- 

 mann, subsequently joined them. From the time of Lavoisier, works 

 had been coming from France in which physiological questions were 

 treated in a thoroughly physical method — the treatises of Dulong 

 and Despretz on heat production and dissipation, those of PoiseuiRe 



