CIRCULAR No 2. 



United States Department of Agriculture, 



DIVISION OF CHEMISTRY. 



WASHINGTON, D. C., December 12, 1896. 



The manuscript embracing the changes in and additions to methods of analysis 

 adopted at the thirteenth annual meeting of the Association of Official Agricultural 

 Chemists, held at Washington, D. C., November 6 to 9, 1896, is respectfully submit- 

 ted for publication as Circular No. 2 of this Division. On account of the great cost 

 of reprinting the official methods of analysis, it is recommended that the changes in 

 and additions to official methods authorized by the association be printed separately 

 for the guidance of analysts during the year 1897. They are to be used as comple- 

 mentary to the official methods published in Bulletin No. 46. 



Kespectfully, H. W. WILEY, 



Chief of Division. 

 Approved : 



CHARLES W. DABNEY, Jr., 



Assistant Secretary. 



CHANGES IN AND ADDITIONS TO METHODS OF ANALYSIS 

 ADOPTED AT THE THIRTEENTH ANNUAL MEETING OF THE 

 ASSOCIATION OF OFFICIAL AGRICULTURAL CHEMISTS. 



[In all cases, unless otherwise mentioned, pages and paragraphs cited refer to Bulletin No. 46, Chem- 

 ical Division of the United States Department of Agriculture. H. W. W.] 



METHODS FOR THE ANALYSIS OF FERTILIZERS. 

 DETERMINATION OF NITROGEN. 



Page 21 (h), third line, substitute for "a large excess of magnesia," "5 grams or 

 more of magnesium oxid free of carbon dioxid." 



DETERMINATION OF POTASH. 



Page 22 (2) (b), first and second lines changed to read: "When it is desired to 

 determine the total amount of potash in organic substances like cotton-seed meal, 

 tobacco stems," etc. 



Page 24, (c) Factors. The following are to be used for computing from the potassium- 

 platinum chlorid: 



(K 2 PtClfi) to KC1 X 0.3069 

 to K 2 SO 4 X 0.3587 

 to K-O X 0.1939 



DETERMINATION OF PHOSPHORIC ACID. 



Page 14 (2) (6) (6,), eighth line, omit "six," and insert "from ten to fifteen." 

 Sixteenth line, omit all after "wash 7 ' to end of sentence and insert "from live to 

 six times with water, using in all from 150 to 250 cc." 



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