Celebration of the Fiftieth Anniversary. Ixiii 



Dr. Long : — 



Mr. Toastraaster, Ladies and Gentlemen : — Some twenty 

 years after the founding of this Academy, the American 

 Chemical Society was organized ; after some years of uncer- 

 tain work and struggle it finally began to grow and has now 

 reached a membership of nearly three thousand. On behalf 

 of the President and Council of the Chemical Society I bring 

 vou orreeting, and cordial wishes for your future. 



The chairman of your Committee has asked me to say a 

 few words on the trend of chemical development in the last 

 fifty years, on the direction in which advance in this science 

 has been the most marked. A brief discussion of the topic 

 is not a simple matter. Fifty years in the life of a science 

 may mean much or little; in bacteriology, modern physiology 

 and pathology it means everything, but in physics, mathe- 

 matics and astronomy it counts for far less. To state the 

 importance of the last fifty years in the history of chemistry 

 is not as easy, and I shall not attempt to say anything of the 

 marvelous growth of chemical technology. 



If we look over some of our books on the history of chem- 

 istry, — the famous work of Kopp, dating from 1843, for 

 example, — we are surprised to find that many of the things 

 which attract our attention now are not even mentioned. 

 Nothing is said of the spectroscope, nothing of ferments as 

 we now know them, nothing of the coal tar dyes, and of our 

 modern equations and reactions there is little that is familiar. 

 If we examine another famous book, the chemistry of 

 Gmelin, the fourth revision of which appeared after 1840, 

 we encounter a nomenclature which is strange to us, and 

 which is hard to read without a glossary. In considering 

 what chemistry has done in the half century we must remem- 

 ber that fifty years ago our modern method of writing form- 

 ulas was not generally recognized, and in the simplest 

 expressions there was much confusion. Water, for example, 

 was represented by at least four different formulas by as 

 many schools of chemists, and this in spite of the fact that 

 at a much earlier period Avogadro and Dulong and Petit had 

 pointed out the criteria by which the atomic and molecular 



