September 8, 1911] 



SCIENCE 



293 



having given the name "electron" to its 

 unit as far back as 1874. His investiga- 

 tions dealt with spectroscopy and allied 

 subjects, and his philosophic mind led him 

 to publish a scheme of ontology which, I 

 venture to think, must be acknowledged to 

 be the most important work which has ever 

 been done on that difficult subject. 



Among our corresponding members we 

 have lost Professor Bohr, of Copenhagen; 

 Professor Briihl, of Heidelberg; Hofrat 

 Dr. Caro, of Berlin; Professor Fittig, of 

 Strassburg; and Professor Van't Hoff, of 

 Berlin. I can not omit to mention that 

 veteran of science. Professor Cannizzaro, 

 of Rome, whose work in the middle of last 

 century placed chemical science on the firm 

 basis which it now occupies. 



I knew all these men, some of them in- 

 timately; and, if I have not ventured on 

 remarks as to their personal qualities, it is 

 because it may be said of all of them that 

 they fought a good fight and maintained 

 the faith that only by patient and unceas- 

 ing scientific work is human progress to be 

 hoped for. 



It has been the usual custom of my pre- 

 decessors in office either to give a sum- 

 mary of the progress of science within the 

 past year or to attempt to present in intel- 

 ligible language some aspect of the science 

 in which they have themselves been en- 

 gaged. I possess no qualifications for the 

 former course, and I therefore ask you to 

 bear with me while I devote some minutes 

 to the consideration of ancient and modern 

 views regarding the chemical elements. To 

 many in my audience part of my story will 

 prove an of t- told tale ; but I must ask those 

 to excuse me, in order that it may be in 

 some wise complete. 



In the days of the early Greeks the word 

 "element" was applied rather to denote a 

 property of matter than one of its con- 

 stituents. Thus, when a substance was said 



to contain fire, air, water, and earth (of 

 which terms a childish game doubtless once 

 played by all of us is a relic), it probably 

 meant that they partook of the nature of 

 the so-called elements. Inflammability 

 showed the presence of concealed fire; the 

 escape of "airs" when some substances are 

 heated or when vegetable or animal matter 

 is distilled no doubt led to the idea that 

 these airs were imprisoned in the matters 

 from which they escaped; hardness and 

 permanence were ascribed to the presence 

 of earth, while liquidity and fusibility 

 were properties conveyed by the presence 

 of concealed water. At a later date the 

 "Spagyrics" added three " hypostatical 

 principles" to the quadrilateral; these 

 were "salt," "sulphur," and "mercury." 

 The first conveyed solubility, and fixedness 

 in fire ; the second, inflammability ; and the 

 third, the power which some substances 

 manifest of producing a liquid, generally 

 termed "phlegm," on application of heat, 

 or of themselves being converted into the 

 liquid state by fusion. 



It was Robert Boyle, in his "Skeptical 

 Chymist," who first controverted these an- 

 cient and medieval notions, and who gave 

 to the word "element" the meaning that it 

 now possesses — the constituent of a com- 

 pound. But in the middle of the seven- 

 teenth century chemistry had not advanced 

 far enough to make his definition useful; 

 for he was unable to suggest any particu- 

 lar substance as elementary. And, indeed, 

 the main tenet of the doctrine of "phlo- 

 giston, ' ' promulgated by Stahl in the eigh- 

 tenth eentuiy, and widely accepted, was 

 that all bodies capable of burning or of 

 being converted into a "calx," or earthy 

 powder, did so in virtue of the escape of a 

 subtle fluid from their pores; this fluid 

 could be restored to the "calces" by heat- 

 ing them with other substances rich in 

 phlogiston, such as charcoal, oil, flour and 



