402 POPULAR SCIENCE MONTHLY. 



periments had to be carried out. I had to make estimations of ash, 

 of albumen, to investigate gluten in plants, etc. The names of the 

 young chemists who helped Liebig were mentioned in the book, 

 among them mine. The proposal was then made to me, just at the 

 time Liebig intended to make me his assistant, that I should go for 

 a year abroad, either to Berlin, which was at that time to Giessen a 

 foreign land, or to Paris. 'Go,' said Liebig, 'to Paris; there your 

 views will be widened; you will learn a new language; you will get 

 acquainted with the life of a great city; but you will not learn chem- 

 istry there.' In that, however, Liebig was wrong. I attended lec- 

 tures by Fremy, Wurtz, Pouillet, Regnault; by Marchandis on 

 physiology, and by Payen on technology. One day, as I was saunter- 

 ing along the streets, my eyes encountered a large poster with the 

 words Legons de philosophie chimique par Charles Gerhardt, ex- 

 prof esseur de Montpellier. Gerhardt had resigned his professorship 

 at Montpellier, and was teaching philosophy and chemistry as privat 

 docent in Paris. That attracted me, and I entered my name on the 

 list. Some days later I received a card from Gerhardt; he had seen 

 my name in Liebig's Letters on Chemistry. On my calling upon 

 him he received me with great kindness, and made me the offer, 

 which I could not accept, that I should become his assistant. My 

 visit took place at noon, and I did not leave his house till midnight, 

 after a long talk on chemistry. These discussions continued between 

 us at least twice a week for over a year. Then I received the offer 

 of the post of assistant to von Plauter, at the Castle of Reichenau, 

 near Chur, which I accepted, contrary to Liebig's wish, who recom- 

 mended me as assistant to Fehling, at Stuttgart. So I went to 

 Switzerland, where I had leisure to digest what I had learned in 

 Paris during my intercourse with Gerhardt. Then I received an 

 invitation from Stenhouse, in London, to become his assistant, an 

 invitation I was loath to accept, since I regarded him, if I may be 

 allowed the expression, as a Sclimiercliemiker. By chance, however, 

 Bunsen came to Chur on a visit to his brother-in-law, at whose house 

 I first met him. I consulted Bunsen as to Stenhouse's offer, and he 

 advised me by all means to accept it. I should learn a new lan- 

 guage, but I should not learn chemistry. So I came to London, 

 where as Stenhouse's assistant I did not learn much. By means of a 

 friend, however, I became acquainted with Williamson. The latter 

 had just published his ether theory, and was at work on the polybasic 

 acids (in particular on the action of PC1 5 on H 2 S0 4 ). Chemistry 

 was at one of its turning points. The theory of polybasic radicals 

 was being evolved. With Williamson was also associated Odling. 

 Williamson insisted on plain, simple formulae, without commas, with- 

 out the buckles of Kolbe or the brackets of Gerhardt. It was a 



