Ixiv Trans. Acad. Sci. of St. Louis. 



weights may be fixed. It remained for Cannizzaro, in 1857, 

 to call attention to these almost forgotten facts and insist on 

 their fundamental importance. Such dates must be kept 

 in mind to appreciate what has been accomplished in fifty 



years. 



In studying the growth of chemistry we easily recognize 

 two o-eneral lines of progress. In the one case we have the 

 question of form, of constitution, of what things are; in the 

 other, of action, of what things do, of function, in other 

 terms. In looking first at the questions' of constitution it is 

 at once apparent that our greatestfinterest seems to be extend- 

 ino" in two directions, and we are not obliged to go back fifty 

 years to trace the beginning of our efforts. To be sure 

 there is always the routine work of making inorganic and 

 oro-anic compounds and much of this has great value ; the 

 journals are full of this, but I have in mind two lines of 

 endeavor of far greater interest, and perhaps of greater 

 scientific importance. In the one direction investigation is 

 concerned with the most minute of material particles out of 

 which, possibly, the larger atoms have grown. Chemists and 

 physicists have long cherished the idea of an ultimate cor- 

 puscle or protyle atom, but only within the last few years 

 have the discus.sions taken any tangible shape. The stud}^ of 

 radio-activity and the discovery of radium mean much for the 

 foundations of chemical theory and may lead to the re-writing 

 of several chapters which we had almost come to look upon 

 as forever fixed. It is doubtless too early to properly recog- 

 nize the full scientific weight of these recent discoveries. 



I must say something now about work in the other field of 

 study, regarding the nature or constitution of matter. While 

 one set of investigators has been busy with the minutest of 

 chemical particles, other workers have been making most re- 

 markable advances in the opposite direction. In the early 

 days of the study of organic chemistry the Dutch chemist 

 Mulder thought he had reached the empiric constitution of 

 the nucleus group in the protein molecule. Formulas were 

 even given for certain proteins. Liebig and others were soon 

 able to show, however, that the}protein molecule is immensely 



