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104 MANNANE AS AN ARTICLE OF HUMAN FOOD. 
There are prepared a powder and a gelatinous mass from 
the root-stock. To prepare the powder, the root-stock is sliced 
into thin pieces after all the skin is removed. These slices are 
hung up to dry, and after several weeks are ground in a mortar, 
and sifted. 
To prepare namakonniaku , as the gelatinous mass is called, 
the powder or the root-stock is well boiled with water, then 
ground into a pasty mass, forced through a sieve, and transferred 
into a large wooden tub, mixed with an equal quantity of slaked 
lime and double the amount of water, and kneaded with the feet. 
After the mixture has become homogeneous, it is boiled with 
lime water until it forms a gelatinous mass. 1 2 ) 
Chemical Investigation- 
The powder of konniciku above mentioned served principally 
for my experiment. It was boiled with 3% solution of sul¬ 
phuric acid for several hours. On filtering a yellowish solution 
was obtained which was neutralized with barium carbonate, 
decolorised with animal charcoal, filtered, and evaporated to 
a syrup, from which no crystals could be obtained. It was 
soluble in cold water and dilute alcohol, had a strong power of 
reducing Fehling’s solution, had a very sweet taste and turned 
the plane of polarization to the right. This syrup consists 
evidently, to a great extent, of mannose, for even a very small 
quantity of it at once gave in the usual way treated in the cold 
with solution of acetate of phenylhydrazin, a colorless crystalline 
precipitate soluble in hot water and hot alcohol, and thus very 
easily purified. The melting point of this purified precipitate 
was found to be 195—20oC J . 
There can be no doubt that this was mannose-phenyl- 
hydrazon, as this substance was easily transformed by further 
treatment with phenylhydrazin into phenyl-glucosazon melt- 
1) The workmen have to avoid inhaling the fine powder by covering the nose 
with a cloth, as the powder irritates the throat. 
2) This mass is made to freeze in winter, whereby its aspect changes; this 
product is preferred and is called “ körikonniaku” 
From the root-stocks, a kind of paste is made which is principally used to in¬ 
crease the lustre of clothes and which is far superior to starch paste, and cheaper 
than the latter. Paper treated with this paste of konniciku, is used instead of oiled 
paper for our umbrellas and water-proof clothes. 
