viii] in the Eighteenth Century. 207 



tions attached to it. Of what is perhaps his greatest work, 

 the establishment of the doctrine of muscular irritability, I 

 shall have occasion to speak in detail in a succeeding lecture. 

 For the present I ivish to speak of him as an expositor only. 

 When we turn from any of the preceding writers on physiology, 

 from any one of those whom I have mentioned in the foregoing 

 lectures, and open the pages of Haller's Elementa, we feel that 

 we have passed into modern times. Save for the strangeness 

 of much of the nomenclature, and for no small deficiencies in 

 all that relates to the chemical changes of the body, we seem 

 to be reading a modern text-book, a modern text-book of the 

 most laborious and exhaustive kind. Haller passes in review all 

 the phenomena of the body. In dealing with each division of 

 physiology he carefully describes the anatomical basis, including 

 the data of minute structure, physical properties, and chemical 

 composition so far as these were then known. He then states 

 the observations which have been made, and in respect to each 

 question as it arises explains the several views which have been 

 put forward, giving minute and full references to all the authors 

 quoted. And he finally delivers a reasoned critical judgment, 

 expounding the conclusion which may be arrived at, but not 

 omitting to state plainly when necessary the limitations which 

 the lack of adequate evidence places on forming a decided 

 judgment. He carefully recounts and as carefully criticises all 

 the knowledge which can be gleaned about any question. If he 

 feels unable to come to a decided conclusion he candidly says so. 

 He always strives to be as exact and as clear as possible ; con- 

 spicuous is the absence from his writings of loose expressions 

 and ill-defined general views such as abound in so many of his 

 predecessors. We may take any part of his great work as a 

 trustworthy account of the knowledge of the time with regard 

 to the questions therein treated. 



The following is a brief sketch of the exposition which he 

 gives of digestion. According to him saliva is neither acid nor 

 alkaline ; and so far from attributing to it the great virtues 

 claimed for it by Sylvius and Stahl, he seems to regard its great 

 use as being that of softening the food and helping deglutition. 

 In the stomach he recognizes the importance of the tunica villosa, 



