CONV^ENTION OF OFFICIAL AGRICULTURAL CHEMISTS. 435 



The after effect of Redoiida pliosphate <in acid soils \\as practii-ally nothing, Tnit on 

 liiiu'd soils was relatively much better, though i)our in comparison with other phos- 

 phates. The common occurrence of acid soils in the United States and the reports 

 that Redouda phosphate is used extensively in the manufacture of mixed fertilizers 

 were pointed out as making this subject one of the utmost importance. It was 

 believed that soils must be put in such a i-ondition as to render Redonda phosphate 

 effective or else methods of chemical analysis must be devised for discriminating 

 against this material. In view of the facts stated it was considered desirable that 

 tlie association take under immediate consideration the methods for the determina- 

 tion of phosphoric acid in commercial fertilizers. 



DAIRY PRODUCTS. 



G. W. Cavanaiigh, as referee on this subject, made no formal report, 

 but recommeiKlod further study of the effect of preservatives upon 

 the all)iuiiin of milk, with special reference to the quantitative deter- 

 mination of albumin. This recommendation was approved. The paper 

 noted below was presented in this connection. 



Note on th.e "Waterliouse test, modified, for the detection of renovated 

 butter, G. E. Patrick. — In the Waterhouse test, as used by the author, the sample 

 is melted in water instead of milk. It was reported that 4 samples of canned oleo- 

 margarine from Europe were found to granulate in this test the same as genuine but- 

 ter, which modified somewhat views based upon earlier work and reported to the 

 association 2 years ago. The results of several tests led the authoi- to suggest tnat 

 the granulation of butter in this test may possibly l)e affected by the pasteurization 

 of the cream from which it is made. 



FOODS AND FEEDING STUFFS. 



The cooperative work done on feeding stuffs during- the year was 

 directed to the determination of fat and crude tiber. The association 

 requested further study by the referee of the composition of the ether 

 extract obtained from the residue from fat determination by the offi- 

 cial method after this residue has been digested with pepsin, and a 

 further comparison of the Konig and official methods for the determi- 

 nation of crude ff])er and the determination of pentosans in the crude 

 residue. A paper submitted by C. A. Browne reported work relating 

 to the occlusion of fat as a source of error in analytical work, and to 

 the determination of acidit}^ in feeding materials. The attention of 

 the association was called by H. W. Wiley to the work of the inter- 

 national connnittee on fertilizers and feeding stuffs concerning uniform 

 methods for sampling. 



Report of referee, F. D. Fuller. — Samples of distillers' grains and bran were 

 sent to 11 analysts with directions for detennining ether extract and crude fiber. 

 In the determination of ether extract a comparison was made of the official method 

 and the Dormeyer method. The average results obtained by the official method 

 were 11.33 per cent for distillers' grains and 5.43 per cent for bran, the calculation 

 being made to water-free substance. The corresponding percentages by the Dor- 

 meyer method were 11.84 and 5.52. showing higher results on both materials by the 

 Dormeyer method. 



