Page:Popular Science Monthly Volume 54.djvu/418

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 chemistry there.' In that, however, Liebig was wrong. I attended lectures by Frémy, Wurtz, Pouillet, Regnault; by Marchandis on physiology, and by Payen on technology. One day, as I was sauntering along the streets, my eyes encountered a large poster with the words Leçons de philosophie chimique par Charles Gerhardt, exprofesseur 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 recommended 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 Schmierchemiker. 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 language, 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 PCl₅ on H₂SO₄). 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, without the buckles of Kolbe or the brackets of Gerhardt. It was a