8 THE POPULAR SCIENCE MONTHLY 



However, the head-master, Romanet, appears to have possessed more 

 discernment than the rest of the faculty; for he frequently engaged 

 young Pasteur in private talks in which he endeavored to arouse in him 

 the ambition to prepare for teaching as a career. 



At graduation, he was offered the position of preparation assistant 

 or coaching tutor to the younger pupils, a post which carried the munifi- 

 cent salary of 300 francs per annum with board and lodging. He ac- 

 cepted the position gladly; and, with charming modesty, expressed the 

 conviction that the salary was much beyond his deserts. 



Small as his salary was, still he managed to save out of it something 

 to help educate his sisters. Meanwhile he worked hard on the studies 

 required for his B.S. degree, a prerequisite to his entering the Ecole 

 Normale Superieure at Paris. On this examination he was graded 

 " mediocre " in chemistry. 



Pasteur had thus far been a hard student ; but he does not appear to 

 have been an enthusiastic one till he had been for some time at the 

 Ecole Normale under the instruction of Balard, the discoverer of bro- 

 mine, who was probably the only real teacher he ever had. 



But even in this highest school for the training of professors af- 

 forded by the France of that day, the scientific equipment was so meager 

 that only a few simple experiments were allowed for repetition by the 

 students of chemistry. An incident in this connection will show the 

 stuff that Pasteur was made of. Not content with being told how phos- 

 phorus is prepared, he bought some bones, calcined them, treated the 

 calx with sulphuric acid, distilled the product with charcoal, and placed 

 the distillate in a vial neatly labelled phosphorus. This was his first 

 scientific joy. His comrades dubbed him " the laboratory pillar." 



About this time he was shown a sample of a strange new acid of the 

 same composition as tartaric acid, but manifesting strikingly different 

 physical characteristics. His curiosity was intensely aroused. 



Tartaric acid had been discovered in the " tartar " of wine casks by 

 Scheele, of Sweden, in 1770. Thann, an Alsatian manufacturer of 

 tartaric aeid, discovered some of the anomalous variety in the output of 

 his factory in 1825. He was unable to reproduce it. It was studied by 

 Gay Lussac and Berzelius in 1826. The latter proposed for it the name 

 of paratartaric acid; the former suggested that it be called racemic 

 acid. Mitscherlich, of Berlin, in 1844 reported it as isomorphic with 

 tartaric acid; and discovered that while the latter rotates a beam of 

 polarized light to the right, racemic acid is inactive in this respect. 



These were the facts brought to Pasteur's attention at the time when 

 he was shown a specimen of the acid. Although immensely interested 

 in the mystery presented by racemic acid, he put it aside, resolving to 

 take it up when through with the final examination of his course of 

 study, an ordeal for which he was just then preparing. 



