330 



SCIENCE 



[N. S. Vol. XLV. No. 1162 



production of the frequency v. This is 

 true, and therein lies its strength, just as 

 the strength of the first and second laws of 

 thermodynamics lies in the fact that they 

 are true irrespective of a mechanism. The 

 Bohr theory is a theory of atomic structure ; 

 it is not a theory of radiation, for it merely 

 states what energy relations must exist 

 when radiation, whatever its mechanism, 

 takes place. As a theory of atomic struc- 

 ture, however, it is thus far a tremendous 

 success. The radiation problem is still the 

 most illusive and the most fascinating 

 problem of modern physics. I hope to dis- 

 cuss it at a later time. 



E. A. MlLLIKAN 

 Eyerson Laboratory, 

 University or Chicago 



GEORGE CHRISTIAN HOFFMANN 



George Christian Hoffmann, formerly as- 

 sistant director, chemist, and mineralogist 

 of the Geological Survey of Canada, died in 

 Ottawa, March 8, 1917. He was born June 7, 

 1837, in London, England, and studied at the 

 Eoyal School of Mines under Sir Henry de la 

 Beche, under Hoffman, Percy, Smyth, Stokes, 

 Ramsay, Huxley and Willis. He spent several 

 years as chemist in research laboratories of 

 England, and later 1861, wrought in Natal, 

 South Africa, in the Mauritius, later again in 

 Australia. In 1872 he joined the technical 

 staff of the Geological Survey of Canada, 

 Montreal, under Dr. Alfred E. C. Selwyn. 

 Dr. Hoffmann was a fellow of the Institute of 

 Chemistry of Great Britain, a fellow of the 

 Eoyal Society of Canada and of many other 

 distinguished bodies. He is the author of 

 many numerous reports published by the 

 Geological Survey of Canada and the Depart- 

 ment of Mines. While in Australia he devoted 

 considerable time in the phyto-chemical labo- 

 ratory attached to the Melbourne Botanic 

 Garden in Victoria ; inquiries into the tanning 

 properties of the barks of native trees; inves- 

 tigation into the amount of potash in vari- 

 ous indigenous trees, besides experiments in 

 reference to various acids, tar and other prod- 



ucts. Besides the above enquiry into the 

 suitability for paper-making of various fibrous 

 substances were carried on by Dr. Hoffmann. 

 The essential oils of certain trees, dyeing 

 properties and coloring matter of others and 

 researches on tea, opium and various economic 

 products were carried out in conjunction with 

 Baron Ferdinand Mueller, the distinguished 

 Australian botanist. His bibliography con- 

 tains valuable reports and papers of analyses 

 and determinations of Canadian ores, min- 

 erals and economic products characterizing 

 the rock formations of Canada and elsewhere, 

 including rare and new species. 



H. M. Ami 

 British Embassy, 

 Washington, D. C. 



SCIENTIFIC EVENTS 



lectures on sanitary science at 



rutgers college 



In connection with the recently established 

 course in sanitary science, Eutgers College has 

 inaugurated a series of public lectures. The 

 list follows: 



November 27. Professor Jacques Loeb, of the 

 department of experimental biology of the Rocke- 

 feller Institute, New York City, " Regeneration. " 



February 5. Dr. J. G. Needham, professor of 

 entomology, Cornell University, "Action." 



February 28. Dr. G. M. Potter, of the Bureau 

 of Animal Industry, Washington, D. C, "Abor- 

 tion Diseases of Cattle. ' ' 



March 7. Professor A. E. Taylor, Ph.D., Uni- 

 versity of Pennsylvania, "Agricultural Production 

 in Germany under Blockade." 



March 8. Mr. Allen Hazen, C.E., New York 

 City, "Purification of Water Supplies." 



March 14. Dr. K. P. Kellerman, associate chief 

 of the Bureau of Plant Industry, Washington, D. 

 C, ' ' Relation of Algse to Public Water Supplies. ' ' 



March 19. Dr. J. P. Anderson, director of 

 Squibb 's Laboratory, New Brunswick, N. J., 

 ' ' Anaphylaxis. ' ' 



March 21. Dr. Theobald Smith, director of the 

 department of animal pathology of the Rockefeller 

 Institute, Princeton, N. J., "Research in Animal 

 Diseases with Reference to Agriculture and the 

 Industries. ' ' 



March 22. Dr. Theobald Smith, director of the 

 department of animal pathology of the Rockefeller 



