46 AMERICAN WHEAT AND CORN. 



The conclusions which Von Bibra long ago expressed concerning the 

 wheats which he had examined seem to hold good for this country as 

 well as for Germany. It is only exceptionally that the inorganic con- 

 stituents of a wheat overstep certain limits, while within them it is 

 liable to frequent variations even on the same field and under otherwise 

 similar conditions. 



The analysis of the ash of the flour from Minnesota shows a marked 

 decrease in the percentage of magnesia which it contains, made up 

 principally by an increased amount of lime. Dempwolff's analyses of 

 Hungarian flours gave a similar result. The phosphoric acid, too, is- 

 higher, showing that in the interior of the grain, and apparently also- 

 in the softer wheats, there is more of this constituent present. 



A discussion of the ash constituents of the grain in its different por- 

 tions will be found in Liebig's Annaleu der Chemie, Baud CXL1X, S. 

 345, by Dempwolff. It is quoted by Horsford, in his report on bread 

 at Vienna in 1873, and attention is called to the decrease in percentage 

 of magnesium in the ash of the center of the grain, accompanied by an 

 increase in calcium and potassium, and the fact that phosphoric acid 

 forms about 50 per cent, of the ash. Determinations of the latter con- 

 stituent in the milling products from Minnesota show that with the 

 hard spring wheats the relative percentage in the ash is higher toward 

 the interior of the grain.* 



In the flours as graded for the market the same fact is observed. 



RELATION OF NITROGEN TO PHOSPHORIC ACID. 



After the consideration of the variations in the ash, it is of interest 

 to observe the relation between the phosphoric acid which it contains- 

 and the nitrogen. A column in the table of analyses gives this ratio r 

 expressed as the factor by which the phosphoric acid must be multi- 

 plied to equal the nitrogen. 



Starting with a ratio of 2.8 in the whole grain, with every purification 

 of the product the figure rises until it reaches the highest grade mid- 

 dlings and patent-flour; that is to say, as we approach the more perfect 

 products there is a greater loss of phosphates than of nitrogen. The 

 highest ratios are found in the patent-flours and in the chop and mid- 

 dlings, which lead directly to this product. In the flours from the re- 

 duction of the different grades of middlings the change in the ratio is- 

 gradual and corresponds closety to the inverse change in the amount 

 of phosphates in the ash. A high ratio denotes, therefore, a deficiency 

 in phosphates, and this is the chief fault with the high grade flours. 



THE GERMS. 



One of the characteristic features of the roller-milling process, as has- 

 been mentioned, is the removal of the germ of the grain, thus prevent- 



* See also Lowe's and Gilbert's paper on the Ash Constituents of Wheat, Town. 

 Chem. Soc. XLV, 305, Aug., 1884, and Appendix of this report. 



