NOVEMBEB 26, 1915] 



SCIENCE 



765 



but, owing to the fact that a dyed gelatine 

 was necessary to obtain a final correction, this 

 unit was limited in application. Since that 

 time both Ives and Brady, and the writer 

 independently produced such filters in a single 

 glass.^ Mr. E. B. Hussey* developed a filter 

 in 1912 for use with the intensified arc. Mees, 

 Pirani, Weertz, and others have also worked 

 on the problem. 



The units developed by the writer have been 

 designed for solving various problems and in- 

 clude accurate color-matching units for the 

 most exacting color-work as well as more effi- 

 cient yet sufficiently accurate units for the 

 rougher color-work. Several thousand of 

 these units consisting of a single colored glass 

 are in daily use and have not only passed the 

 spectrophotometric tests, but the tests of many 

 different practical applications. The writer^ 

 emphasized the application of these units in 

 microscopy and besides being applied to this 

 field, many units are in daily use in color- 

 matching, lithography, cigar sorting, medical 

 diagnosis, horticulture, oil refining, surgery, 

 color photography, hair dressing, art exhibits, 

 painting, paint factories, chemical laboratories, 

 laundries, in millinery, dry goods, clothing 

 and jewelry stores, textile mills, art schools, 

 paper mills, and many other places. 



m. luckiesh 



Nela Research Laboratokt, 

 National Lamp Woeks op G. E. Co., 

 Nela Park, Cleveland, Ohio 



injections of the bundle of his 



To THE Editor of Science : In a letter pub- 

 lished in Science of November 12, 1915, Dr. 

 A. W. Meyer, of Stanford University, com- 

 plains that injustice has been done to his 

 former associate. Dr. Lhamon, who devised a 

 method of injecting the bundle of His, by the 

 publication of a note by Dr. Cohn describing 

 hearts injected by this method, before the ap- 

 pearance of Dr. Lhamon's paper. 



s Trans. I. E. S., Vol. 9, p. 840, p. 937, 1914; 

 Ulec. World, Sept. 17, 1914; Jour, of FranUin 

 Inst., Vol. 177, p. 471, 1914; Eleo. World, Apr. 4, 

 1914. 



4 Trans. I. E. S., Vol. 7, p. 13, 1912. 



6 Elec. World, July 10, 1915. 



The circumstances were as follows : Dr. 

 Meyer showed me the injections when I was in 

 his laboratory in California and, on my return, 

 as the preparations had interested me very 

 much, I spoke of them to a number of men 

 including Dr. Cohn. I made it clear at that 

 time that the method had been devised by one 

 of Dr. Meyer's assistants and every one who 

 heard of it was aware of this. Dr. Cohn was 

 not then my assistant, but was working at the 

 Eockefeller Hospital, where he experimented 

 with the method in connection with his own 

 work. 



Dr. Meyer's letter is so worded that it might 

 give the impression that I, after an apparently 

 friendly visit, betrayed his confidence by hav- 

 ing an assistant anticipate his publication of 

 the new method. This is unfortunate, for I 

 can not believe that he intended to imply such 

 a thing. 



The publication was not made by one of my 

 assistants, nor at my suggestion, nor even vsdth 

 my previous knowledge of its nature. Fur- 

 thermore I was not present at the meeting of 

 the 'New York Pathological Society when the 

 injected hearts were demonstrated, else I 

 should have emphasized the fact in the discus- 

 sion that this was a method devised in Dr. 

 Meyer's laboratory. liTevertheless it appears 

 in the published discussion that the method 

 had first been heard of through me. 



I am impelled to write this in defense of Dr. 

 Cohn, because I feel convinced that he had no 

 intention of claiming priority. Every one con- 

 nected with the matter regrets exceedingly the 

 inopportune publication of the first note and 

 the carelessness which let it pass into print 

 without definite mention of Dr. Lhamon's 

 work. W. G. MacCallum 



College of Physicians and Surgeons, 

 Columbia University, 

 November 18, 1915 



To THE Editor of Science: In Science of 

 ISTovember 12, 1915, appears a letter from Pro- 

 fessor A. W. Meyer, of Stanford University, 

 in which, in behalf of his former associate. Dr. 

 Lhamon, he very vigorously asserts a claim for 

 priority in injection of the conduction system 

 in mammalian hearts. If the sole purpose of 



