NOVEMBEK 5, 1920] 



SCIENCE 



433 



until the cumulative power of the intellectual 

 ^and social ferment induced became so great as 

 to be irresistible, and the whole mass was 

 moved forward. 



From the outset Welch was the central 

 figure and guiding genius of the medical 

 group. The pathological laboratory became 

 an active center of research and teaching. 

 Welch's life quickly became filled to overflow- 

 ing. He conducted investigations of his own, 

 launched others on productive themes, and 

 saw to it that the invaluable pathological 

 specimens from the surgeons and gynecolo- 

 gists were made use of to advance knowledge 

 and train a generation of special pathologists 

 in those important fields. He lectured on 

 special and general subjects in pathology and 

 bacteriology in a manner so learned and 

 fascinating as to produce impressions not only 

 immediately stimulating to his auditors in 

 high degree but of enduring permanence. 

 The suggestiveness of these lectures led fre- 

 quently to new undertakings in research. 

 Moreover, the autopsies he performed, his 

 demonstrations of gross pathological speci- 

 mens and his teachings at the microscope 

 stand out as unsm^assable models. He 

 entered also into the medical activities of 

 Baltimore and of the state of Maryland, and 

 became a great influence for betterment in 

 private and public medicine. He was, of 

 course, the first dean of the medical school 

 and guided the policy of the new institution 

 into the productive chaim.els that have so 

 eminently distinguished it. His many talents 

 were therefore called into constant play, and 

 heavily overtaxed as they must often have 

 been there was never indication of exhaustion. 

 When occasion arose he was always ready, 

 eager and able for a new advance, as witness 

 his leading part in the recent development of 

 the full-time system, so-called, in the clinical 

 branches of medical teaching, in establishing 

 a model school of public health and hygiene, 

 and in serving on scientific and philanthropic 

 boards possessing great wealth, for promoting 

 scientific discovery and for carrying the 

 benefits of medical knowledge to the furthest 

 parts of the world. 



The achievements of Welch as an investi- 

 gator, teacher and reformer in medicine are 

 BO many and varied that it is not possible to 

 do justice to them in detail in a mere sketch. 

 This is particularly true of that part of his 

 career covered by the Baltimore and Johns 

 Hopkins period. These three noble volumes 

 of his collected papers and addresses are the 

 best expression of his many-sided activities. 

 And yet precious as they are, they afford no 

 real insight into Welch's almost flawless per- 

 sonality, the depth of his friendship and 

 wealth of his kindness, his faculty of intense 

 application and devotion to the work in hand 

 whether in laboratory or in public interest, 

 his commanding influence and guiding spirit 

 over the work of his associates and many 

 pupils, the stimulating wholesomeness of his 

 public activities, and his rarely unselfish and 

 tolerant nature which led him to shower his 

 great gifts prodigally and far and wide. The 

 recipient of almost every honor in the gift 

 of his colleagues, he fortunately, in time, saw 

 the return of his labors, increased many-fold, 

 enriching science through progress made in 

 education, in deeds performed and discoveries 

 by the men and institutions over whose 

 destinies he had presided. And lastly these 

 volumes faU to show us still another side of 

 Welch's accomplishments as remarkable al- 

 most as those of the science we so love to laud 

 in him. I refer to his culture outside the 

 realm of medicine in the field of literature, in 

 which he possesses an almost unerring taste 

 for the best in poetry and prose, and in the 

 domain of the fine arts. His mind is indeed 

 stored with the beautiful creations of other 

 men's minds from ancient times to our own 

 day. It is to all these remarkable qualities, 

 innate and acquired, united in one man, that 

 we owe that thrice rare personality William 

 Henry Welch, master in medicine and beloved 

 of men. Simon Flexner 



THE STRUCTURES OF THE HYDRO- 

 GEN MOLECULE AND THE 

 HYDROGEN ION 



In a letter to Science published June 18 I 

 described a model for the helium atom which 



