196 EIGHTEENTH CENTURY. FT. in. 



to good account. When medical students are going to pass 

 their last examination they are required to write an essay, 

 or thesis, as it is called, before they can receive their degree 

 of doctor. Haller used always at these times to propose to 

 each one of his students some difficult point in anatomy or 

 physiology, in which he thought new discoveries might be 

 made, and he then drew out a plan for them and showed 

 them how to begin. By this means their essays were often 

 full of new and useful information, and it was a great deal 

 owing to the help of his pupils that Haller was able to 

 publish 1 80 volumes on science, all. more or less valuable. 



There was also a very good anatomical theatre at Gb't- 

 tingen, and from dissections made there Haller produced 

 a set of most beautiful anatomical drawings, which he pub- 

 lished between 1743 and 1753. You will remember that 

 Vesalius published many fine engravings of parts of the 

 human body (see p. 65), and since his time many others 

 had been made, especially by Haller's master, Albinus. But 

 Vesalius' drawings were coarse, because he had no micro- 

 scope to help him, and Albinus had only drawn separate 

 parts, such as a muscle, a nerve, or a veia Haller's plates 

 were the first which showed the different nerves and vessels 

 attached in their right position, and to each plate he added 

 a complete history of the function, or use of the parts 

 drawn. He made these drawings so accurate, and spent so 

 much time upon each minute structure, that in seventeen 

 years, with all the help he had, he was not able to complete 

 the description of the whole human body. 



Haller discovers the Power of the Muscles to 

 Contract. It was while he was at work at these dissections, 

 that he made one great discovery, which you must try to 

 understand. If you clasp your right hand round your left 

 arm, just above the elbow, and then bend your left arm, you 



