United States Department of Agriculture, 



BUREAU OF CHEMISTRY Circular No. 30. 



H. W. WILEY, Chief of Bureau. 



CHANGES IN OFFICIAL METHODS OF ANALYSIS AND ADDITIONS 

 THERETO, 1899 TO 1905. 



INTRODUCTION. 



Since the adoption of the official methods of the Association of 

 Official Agricultural Chemists as issued in 1899 the work of the asso- 

 ciation has been greatly extended in scope and has also become greatly 

 specialized; in other words, the growth of the work has been both 

 extensive and intensive, both along general lines and in the matter 

 of detail. When, therefore, an effort was made to revise the methods 

 by merely incorporating the changes and additions formally author- 

 ized by the association in convention, it was found that such a revision 

 would be very inadequate, if not absolutely misleading. The follow- 

 ing points are mentioned as illustrative of the character of the changes 

 which should be authorized : 



1 . In the progress of the work along various lines all under different 

 referees, said referees changing from year to year, new methods have 

 been adopted provisionally which conflict' with those under other 

 captions. For example, the very extensive changes made in the 

 methods of sugar analysis have not yet been incorporated under the 

 food adulteration subjects including such determinations (i. e., saccha- 

 rine product^, wines, fruits and fruit products, etc.). 



2. Resulting from the same process as that indicated in paragraph 1, 

 there is much unnecessary repetition and overlapping of the methods, 

 especially in the case of the food methods, ash and moisture determi- 

 nations, etc. This condition calls for the rearrangement of the 

 methods and the grouping together of the general methods to which 

 reference may be made from the specific heads, while under the latter 

 the slight modifications necessary to adapt the general method to the 

 special subject may be given. The following scheme of rearrangement 

 is submitted for consideration: 



ARRANGKMENT OF PROPOSED REVISION OF BULLETINS 46 AND 65.& 



PART I. 



i j . . , i 



Fertilizers. Waters. 



Soils. \^A Insecticides. 



Ash. Tanning materials* 



a Methods adopted by the Association of Official Agricultural Chemists, November 11, 12, 

 and 14, 1898, and issued as Bulletin No. 46, Bureau of Chemistry. 



& Provisional methods for the analysis of foods adopted by the Association of Official 

 Agricultural Chemists, November 14, 15, and 16, 1901, 

 30625 No. 3006 1 



