AGRICULTURAL EXPERIMENT STATION. 37 



METHODS OF DETERMINING SUGAR AND STARCH. 



J. M. Bartlett. 



Acid Method. The sugars are determined by the method de- 

 scribed in Report Maine Experiment Station, 1888, page 207 and 

 the acid method employed to extract starch was that given on page 

 208 of same report, except that a one per cent instead of a one- 

 half per cent HC1 solution was used. 



Diastase Method. Four grams of the finely ground fodder are 

 digested with 50 c. c. water on the steam-bath for one hour, and 

 then 50 c. c. of a freshly prepared extract of malt are added. (The 

 extract is made by placing fifty grams of powdered malt in a liter 

 flask, filling to the mark with distilled water, and then after stand- 

 ing two hours with frequent shaking, the liquid is clarified by pass- 

 ing through a double filter. ) 



The digestion with the malt is carried on at a temperature of 65° C 

 for four or five hours, which is sufficient time to bring the starch 

 all into a soluble condition, no more being obtained by treating 

 longer. This was shown by several trials. This liquid is then 

 passed through a linen filter and the residue thoroughly washed 

 with warm water, bringing the volume up to about 200 c. c. To 

 complete the conversion of the starch to sugar, 20 c. c. of HC1 

 (Sp. gr. 1.125) are now added and the whole digested on the steam- 

 bath for three hours. After cooling, the liquid is neutralized with 

 caustic potash, then four or five c. c. basic acetate of lead are added, 

 the volume made up to the mark (200 c. c.) and filtered through a 

 dry filter ; 25 c. c. are then treated with Fehling solution, in the usual 

 manner. If any lead remains in the solution, it must be removed 

 with sulphurous acid before the Fehling solution is added. 



