AGRICULTURAL EXPERIMENT STATION. 



209 



containing 5 c. c. concentrated HCl at 100° C. for eight hours, then 

 one-half hour with alkali as by the regular crude fibre determination 

 and the result was about five per cent less fibre than when treated one- 

 half hour with one and one-fourlli per cent sulphuric acid in the usual 

 manner. As a further test, five grams of crude fibre were treated by 

 Mr. Ladd's method and the extract tested with Fehling solution. 

 The amount of copper oxide precipitated was equivalent to six and 

 four-tenths per cent of starch. 



By boiling a fodder one-half hour with a one-half per cent HCl 

 solution as much material that reduces Fehling solution is rendered 

 soluble as when a 1 .25 per cent Sulphuric Acid is used. The follow- 

 ing fodders were treated with both acids. 





Equal to Starch. 





One-half per cent. 

 H CI. 



One and one-quarter 

 per cent. 



H^SO, 



Sample A, Corn fodder 



13. ■! 

 15.16 

 13.80 

 9.31 



12,7 



" B, Red top 



" C, Timothy 



16.0 

 13,5 





9,17 







HCl was employed to bring the starch into solution for the rea- 

 son that it is considered more favorable to the conversion of starch 

 to sugar than sulphuric acid, and a mixture of acids during the 

 latter part of the process was not desirable. 



The strength required was determined by making a number of 

 crude fibre determinations, substituting HCl solutions of varying 

 strengths for the 1.25 sulphuric acid, uutil one was found that gave 

 practically the same crude fibre. 



The treatment with acid removes nearly all the matter that, 

 reduces Fehling solution which is extracted in a crude fibre deter- 

 mination, but a small amount being found in the alkali solution.. 

 Several alkali solutions that were examined contained less than two- 

 per cent and as high a percentage of starch was obtained by boiling- 

 the substance one-half hour with water previous to treating it with 

 acid as when both alkali and acid solutions were used. 



14 



