266 



SCIENCE 



[N. S. Voii. LI. No. 1315 



THE AWARD OF THE BOYLE MEDAL 



The presentation of tlie Boyle Medal to H. 

 H. Dixon on January 23, 1917, by Lord Eatli- 

 donnell is now a matter of somewhat ancient 

 history to his colleagues of the Royal Dublin 

 Society. Due to delay in transmission of 

 periodicals, however, the account of the presen- 

 tation and the bibliography of Dr. Dixon's 

 more than three score contributions to science 

 have only just reached America in printed 

 form.^ Because of the widespread interest in 

 Dixon's work on the rise of water in trees, the 

 writer is hastening at this late hour to do honor 

 to a brilliant career and a gentleman of scien- 

 tific vision. 



The tension theory of the ascent of sap in 

 trees was published in 1894 in collaboration 

 with Dr. John Joly. The latter, also, is favor- 

 ably known in America as a physical geolo- 

 gist and mineralogist and a graceful writer of 

 essays on scientific topics, ranging all the way 

 from the "Birth-Time of the World" to 

 " Skating " and " Pleochroic Halos." He also 

 visited the United States as a member of the 

 British Education Commission two years ago. 

 Many of Dr. Dixon's earlier researches were 

 undertaken with Dr. Joly. Dr. Dixon's prin- 

 cipal scientific labors may be classed under 

 three main heads: Cytology and genetics, the 

 path of the transpiration current, and cryo- 

 scopy and thermo-electric methods. 



Contributions to cytology include fertiliza- 

 tion of Pinus sylvestris and some significant 

 work on reduction division and mitosis which 

 aided about a decade later in the rediscovery 

 of Mendel's law. However, transpiration soon 

 began to be Dixon's chief topic of experiment 

 and research and his results will doubtless re- 

 main one of the great contributions to botan- 

 ical science. During the interval between 1894 

 and 1914 investigations concerning the resist- 

 ance experienced by the transpiration stream 

 and theories to account rationally for the up- 

 ward movement of water were developed. Most 

 of the methods employed in these researches 

 were devised by Dr. Dixon and only a few were 



1 Award of the Boyle Medal to Professor Henry 

 Horatio Dixon, Sc.D., P.E.S., Sci. Proc. Eoy. Dublin 

 Soc, 15: 179-184. Anon. 



in collaboration with students. It is, then al- 

 most entirely due to his genius and patient ef- 

 fort that the epochal discoveries come into 

 being. His records of this work are contained 

 in the monograph " Transpiration and the As- 

 cent of Sap," published about 1914. Previ- 

 ously he had been invited to contribute to 

 Progressus Bei Botanicw on the same subject. 

 The third line of investigation has been largely 

 in collaboration with Dr. W. R. G. Atkins. 

 Osmotic pressure changes and cryoscopic and 

 conductivity measurements on saps have been 

 particularly dealt with. These researches are 

 still continuing and have been amplified re- 

 cently by new attacks on the many problems 

 of photosynthesis, especially the increase of 

 sucrose rather than the hexoses following inso- 

 lation. There is no doubt but that much valu- 

 able information will result from this field of 

 investigation. 



The closing sentences of the biographical 

 note {loc. cit.) seem to indicate that Professor 

 Dixon has been accomplishing this magnificent 

 amount of experimental work at the same time 

 that he was teaching " large classes " of med- 

 ical students. The more honor to him. One 

 can not help feeling, however, the stupidity of 

 university organization which permitted his 

 time to be occupied during the best years of 

 his life in work which was relatively unproduc- 

 tive for the science of botany. J£ such an in- 

 spired worker can not impress the governing 

 board of the school with the importance of 

 fundamental research, the outlook for most of 

 us is indeed dark. 



A. E. Waller 



The Ohio State Univeesity 



in honor of william h. welch 

 On April 8 Dr. Welch reaches his seven- 

 tieth birthday. Such an occasion ought not 

 to pass without some new expression of affec- 

 tion and admiration on the part of the med- 

 ical profession of America to one who has 

 long stood as its leader. To many of his 

 friends it has seemed that an expression 

 worthy the master would be the preservation 

 in suitable form of the chief contributions 

 from his pen. 



