148 HERMANN VON HELMHOLTZ 



not myself go back on my promise to B., but should be 

 justified in breaking it, if the demand were made by the Faculty. 

 B. himself did not seem to object/ 



At first Helmholtz was fully occupied with his lectures in 

 anatomy, and as the immediate result he made a short com- 

 munication to the Nieder-Rheinische Gesellschaft on March 12, 

 1856, ' On the Movements of the Thorax/ in which he threw 

 himself into a controversy as to the intercostal muscles. 

 He concluded that the leverage of the upper ribs was the 

 strongest, while it becomes weaker from above downwards, 

 so that the thorax must be regarded as a basket of elastic 

 hoops, each of which has its position of equilibrium, from 

 which it is shifted during inspiration by the pull of the muscles, 

 and which it recovers by its own elasticity in expiration, 

 since expiration in quiet breathing seems to be effected merely 

 I by the relaxation of the inspiratory muscles. 



He found great satisfaction in his scientific and pedagogic 

 functions in this new field, and writes at the close of the first 

 winter session, March 6, 1856, to his father : 



' All has gone well so far in my official relations. To-morrow 

 will be the last of my lectures. The audience has kept fairly 

 up to the mark, and the older students, who are taking Anatomy 

 for the second time, have told me repeatedly that I have 

 shown them and told them much that had escaped them before. 

 So I am justified in hoping that I shall succeed with the 

 Anatomy Lectures, and things will go better when I have got 

 the Museum into order. It has been frightfully neglected.' 



But while Helmholtz believed that he had been successful 

 in the anatomy lectures, du Bois writes to him on April 27, 

 1856, on Lehnert's authority, that it had been reported to the 

 Ministry that his lectures in anatomy were inadequate. Du 

 Bois replied to Lehnert that while all things are possible, 

 and stupidity probable, this was not only improbable, but 

 also impossible; whereupon Lehnert, after giving him the 

 source of the mischievous report, begged him ' to reassure the 

 Minister personally, since he was suffering pangs of conscience 

 for having made such bad provision for Anatomy at Bonn'. 

 Helmholtz replies to du Bois on May 3 : 



1 The report made to the Minister annoyed me ; since it is 

 not even an exaggeration of facts, but is a pure invention, 



