December 29, 1916] 



SCIENCE 



919 



cent, of the total). At Vienna nearly two 

 fifths of the medical students are women. 



The following promotions have been made 

 at the College of the City of New York : From 

 instructors to be assistant professors: Philos- 

 ophy, Dr. Howard D. Marsh ; mathematics, Dr. 

 Paul H. Linehan; chemistry, Dr. Eobert W. 

 Curtis and Dr. William L. Estabrooke. From 

 assistant professorships to associate professor- 

 ships: Physics, Dr. Joseph G. Coffin. 



At the Iowa State College Dr. Charles A. 

 Mann, of the University of Wisconsin, has 

 been appointed associate professor of chemical 

 engineering to succeed Professor George A. 

 Gabriel, who goes into practical work. 



DISCUSSION AND CORRESPONDENCE 



A REPLY TO "METHODS OF CRITICISM OF 

 'SOIL BACTERIA AND PHOSPHATES'" 



In the issue of Science of November 3, 1916 1 

 Drs. Hopkins and Whiting have taken occa- 

 sion to arraign me for having sent to certain 

 editors of agricultural papers a letter headed 

 " Confidential and Not For Publication." 

 They also impugn my motives in writing the 

 letter, for they say it was evidently done to 

 " belittle " the importance of their work, 

 whereas my reason for doing so is explained 

 very fully in the second paragraph of the letter, 

 appended below, and as stated, it was sent to 

 the editors because the work of Hopkins and 

 Whiting was " unfortunately being used by 

 some writers for the purpose of making it ap- 

 pear that the same reaction will take place in 

 the soil in connection with raw rock phos- 

 phate to essentially the same extent." 



Instead of publishing my letter in full, Drs. 

 Hopkins and Whiting quote only certain parts 

 because of alleged lack of " space," but space 

 was taken, nevertheless, to enter into a 

 lengthy discussion of the validity of the work 

 of Professor Mooers and of Director Thorne 

 on raw rock phosphate, and the intimation was 

 made that I had overlooked some work of the 

 latter. This was seemingly not germane to 

 the real issue, for instead of my having at- 

 tempted to review their work, I wrote to each 



iVol. XLIV., No. 1140, p. 649. 



of them asking what their results actually 

 showed, and merely quoted, with permission, 

 from their letters. In fact, these letters were 

 of a later date than the literature cited by 

 Hopkins and Whiting in refutation of Mooers' 

 and Thome's conclusions. 



It will be seen, therefore, that the attack by 

 Hopkins and Whiting on these statements re- 

 solves itself into an allegation that Professor 

 Mooers and Director Thorne were, in their 

 opinion, incompetent to analyze their own 

 work properly or had misrepresented it to me. 

 This fact I regret exceedingly, for no agri- 

 cultural investigators in the United States are 

 held in higher esteem by their colleagues than 

 Mooers and Thorne, and hence such allegations 

 can only result in injury to those who make 

 them. 



Had my letter been intended as an unfavor- 

 able criticism of the work of Hopkins and 

 Whiting, they would most assuredly have 

 been favored with a copy immediately. It 

 was, however, only intended, as stated in the 

 letter itself, as a criticism of the improper use 

 that other persons were making of their results. 



I take pleasure in introducing below my 

 letter of July 28, 1916. The reader is asked 

 to note carefully if the letter constitutes an 

 unfavorable criticism of the work of Drs. 

 Hopkins and Whiting or if, as intended, it is 

 merely an appropriate warning to the agri- 

 cultural press not to draw too far-reaching and 

 improper conclusions from it, for this is the 

 real point at issue. 



Boston, Mass., July 28, 1916 

 Confidential and Not For Publication 



Dear Sir: My attention has been called within a 

 few days to several articles appearing in the agri- 

 cultural press which have been inspired by Bulletin 

 No. 190 of the Illinois Agricultural Experiment 

 Station. It appears that Drs. Hopkins and Whit- 

 ing have experimented with the microorganisms 

 which produce nitrous and nitric acid by the oxi- 

 dation of ammonia. The work was done in water 

 cultures into which artificially prepared and puri- 

 fied tricalcium phosphate had been introduced. 

 They claim to have shown that the nitrite bacteria 

 caused the lime and phosphoric acid of a highly 

 insoluble phosphate to become soluble. 



While this work is of much value as a scientific 

 contribution, it is unfortunately being used by 



