27 



Tlieiu is 11 tliffei'encc -between the twD results of 3. "4, wliieli is not more than 

 iniglit lie eanst'll liy errors of experiiiieiit. If we assumed the solution to contain 

 dextrin ;uid dextrose, tlie specilie rotatory power would be only 174°, a difference 

 of nearly 17^. This ex[icrin)eiit, tlierefore, shows that maltose and not dextrose, 

 is formed. 



Expur'uiicnt 8. ") grams of stareh were gelatinized and after eooliug to 

 40°C. mixed with 2Ö c.c. of the same koji extract and kept at that tem])eratnre 

 Ibr i honr. An additional 2Ö c.e. of koji was then added and the whole allowed 

 to remain at 400. lor \7) \n\\\. longer, then boiled and diluted to 250 c.c. 

 After nitration the solution contained, deduction having been made for the koji 

 added, 



Solid matter 2.035 grams in 100 c.c. 



8ng-ar (calcil. as dextrose). .888 ,, ,, ,, 



Opticixi rotation 28.5 divisions 



Hence ["]^ observed = 169^..) 



Tlie composition of the solution, assuming the sugar to be maltose, is 



Maltose 71.54 percent. 



Dextrin 28.46 ., „ 



100.00 



The s})ecific rotatory power calculated for this mixture is 16S°.8, wliich agrees 

 very closely with the observed number. 



Evjjerhtient fl. With a solutiou pre|>ared from ditVereut koji, using 50 c.c. 

 of the koji solution containing 1.20(j gram of solid matter per 100 c.o., the follow- 

 ing results were obtained from 5 grams of gelatinized starch kept for 2 hts. at 

 10-15°C. 



Maltose 70.00 per cent. 



Dextrin 30.00 „ „ 



lOO.U") 



Specific rotatory power, okserved = 174-'.0 

 „ ,, „ calculated = WJ-'.S 



Tlie two last experiments give results wliicli correspond nearly with IJrown 

 and Heron's equation, No. 7. 



10 lC"Ho„0,„:) -{' 7 HXJ = 7 C'-H.,0„ ;- 3 0'-ll,„0„ 

 wliich requires 70.1) percent, ofmalto.se, and [«J^ calculated = ir)0^.2 



Solutions in which maltose can be detected can only be obtaineil by making 

 use of dilute solutions of ki>ji and in comparatively small ({uantity. In by far the 

 greater number of ex|)eriment.s the malt'ise wliich is at tirst formed is hydrated to 

 dextrose by the excess of '.'diastase " present in the koji solutinn, and iis in the 

 brewing operations a very large excess ul' koji is used, the brewer of sake has 

 practically nothing to do with maltose, but only with dextrose. In this respect 



