lUO;).] 



PUBLIC DOCUMENT — No. 31. 



143 



(c) Determination of Sulfates. 



Sulfates were determined in the watery extracts of several 

 products in the usual way,^ blank determinations being run in 

 every case. 



Number of Sample. 



Total Acidity 

 calculated a.s Sul- 

 phuric Acid. 



Sulfates 

 calculated as Sul- 

 phuric Acid. 



A, 

 B, 

 C, 

 462, 



.0001 

 .0005 

 .0020 

 .1.1.50 



For explanation of numbers see Determination of Chlorides. 



It is evident from the above results that the addition of the 

 steep water causes an increase in the water-soluble sulfate 

 content of the feed. This is accounted for by the fact that the 

 steep water carries more or less of sulfite which is readily oxi- 

 dized, appearing as sulfate. It is doubtful if any sulfate exists 

 in the feed as free sulphuric acid from the fact that it would be 

 readily neutralized, and that it would react acid to methyl 

 orange even though it be present in .small quantities. 



{d) Pliosphoric Acid and Composition of Ash. 

 A water extract of a gluten feed was prepared by bringing 50 

 grams of the sample on a filter and washing with warm distilled 

 water until the filtrate equaled 500 cubic centimeters. This was 

 evaporated to dryness on a water bath and carefully ashed. An 

 anal^'sis of the ash gave the following results : — 



Per Cent. 



