464 ANNUAL. REPORT OF THE Off. Doc. 



PROF. HOPKINS: There is none of it applicable now; I don't be- 

 lieve there is enough potassium or nitrogen on any farm, today 

 applicable, to make a crop of corn. It is gradually liberated during 

 the season. 



QUESTION: What about basic slag? 



PROF. HOPKINS: As you draw slag from- steel works, it is cer- 

 tainly very valuable, but I would not place any more value upon it 

 than upon any other form of phosphorus. The bone materials I 

 count of as much value. The only difference is that the slag carries 

 with it some lime. Now, lime is cheaper than phosphorus, and 

 when you can get pure ground calcium carbonate so cheap, you don't 

 put much value in what is carried in slag. But if you can get the 

 phosphorus in slag as c&eap as you can in acid phosphorus I would 

 take the slag for the lime. 



QUESTION: What is the action of slag? 



PROF. HOPKINS: W^ell, I suppose in a high grade of slag, the 

 phosphoric acid would be about 7 per cent.; phosphorus about the 

 same, possibly from IG to 18 per cent, of acid phos])horus. It is 

 about as rapidly applicable as the bone, and acid phosphorus. It is 

 not quite as soluble, 



MR. WING: Now, I rather agree with the Professor when he 

 says that when the phosphorus is taken out of the soil the crops will 

 not grow, but when it is put back, it produces more than 100 bush- 

 els per acre. I am glad to note that he sets the standard at 100 

 bushels. What did you average, Professor? 



PROF. HOPKINS: About 88 bushels on the average, 70 pounds 

 to the bushel. 



The CHAIRMAN: Are there any further questions on this point? 



The SECRETARY: Now, Mr. Chairman, I take a great deal of 

 credit in asking Prof. Hopkins to come all the way from Illinois. 

 He manifested a willingness to come, if it was possible that he 

 could be of any service to us here. Now, I think he manifested such 

 a courtesy in coming to us to talk so interestingly and instructively 

 that it is worthy of a vote of thanks, and I move that we tender him 

 a rising vote of thanks. 



Duly seconded and agreed to, a rising vote of thanks was ten- 

 dered to Prof. Hopkins. 



On motion, seconded and agreed to, adjourned until 7:30 P. M. 



Wednesday Evening, January 23, 1907. 

 The meeting came to order with Mr. McClellan in the Chair. 



The CHAIRMAN: The first number on the program is the report 

 of the Committee on the Identification of Fruit. Is Dr. Funk ready 

 to report? 



