K. MivAKE : On the Naiube of the Suoabs found ra the Tubers of Abhowhead 31 



4. Experiment with the residue {III). 



Ou tlie qualitative tests, the residue (III) lias shown almost the same 

 reactious as those of the residue (I). A trial was then made to separate and 

 detect the sugar which contains the galactose group. First, we examined, liow 

 much mucic acid would bo produced from the residue by oxidation and the 

 following result was obtained. 



0.2 gram of the residue was put in a small beaker, to wliich nitric acid of 

 sp. gl-, 1.15 was added and oxidized in a boiling water bath as in the usual 

 manner. The mucic acid produced was collected on the filter and weighed 0.00C5 

 gram cori'esponding to 3.25^^. 



Next, we tried to determine its specific rotatory jjower and the result obtained 

 was as follows : 



0.1163 gram of the residue was dissolved in water and made up into 10 cc. 

 and polarized in 100 mm. tube. The rotation was observed to be 2.8 on the 

 scale toward the right. The specific rotatory power is 



, s P ^ 2.8 X 0.316 X 10 _ ^ g3 35 ^i 20°) . 

 ^ 0.1163 X 1 ^ 



If the sugar imder question be rafiinose, the amount of this sugar correspond- 

 ing to 0.0064 gi'am of mucic acid would be 0.087 gram according to Creydt'\ 

 If we assume that sucrose be formed besides raffinose, the quantitative ratio of 

 sucrose and raffinose in the residue (III) would be 1.3 : 1. Upon this ratio, if 

 we calculate the specific rotatory jjower of tlie sample, we will then find the 

 following value which well coincides with tliat of actually observed facts, i.e. 



(66.803^^ X 1.3) + (104.^>xl) _ g^ gg 

 2.3 



Methyl alcoliol, which was recommended for raffinose, was found to be a good 

 solvent for the extraction of the sugar under examination. Hence, a small amomat 

 of methyl alcohol was added to the total residue (HI), well mixed and decanted. 

 This operation was repeated until the bulk of the residue insoluble in methyl 

 alcohol was reduced to about half of its original volume. The combined extracts 

 were evaporated to a syruji. The syrup did not show any sign of forming 



1) Creydt,- Zs. d. Ver. d. D. Zuckerind., Bd. 37, P. 153 ; Lippmann,- Chemie d. Zuckerarten, 

 Braunschweig, Bd. U. P. 1652, (1904). 



2) Specific rotatory power of sucrose according to Tollens. 



3) Specific rotatory power of niflinose according to Tollens. 



