METHOD FOR THE DETERMINATION OF GALACTAN. 
341 
rated down to one-third volume of the original solution. After allowing 
to stand twenty four hours, add lOcc. of water and allow it to stand another 
twenty four hours or longer if necessary. In the mean time the mucic acid 
will be crystallized. Collect the mucic acid on a tared filter or gooch, wash 
with cold water, then with alcohol, and finally with ether, dry at the tem- 
perature of boiling water and weigh. 
In this process, the use of ammonium carbonate solution is entirely dis- 
pensed with, as it has been found by actual experiments that the results 
with or without the purification process are in perfect accord. The results 
of the experiments follow. 
Table IV. 
Sample. Method. Mucic acid obtained. 
j Not purified. 
0.1557 
Natural 
stuff 0 
- Purified with ammonium ear- 
( bonate solution & nitric acid. 
0.1555 
1 Not purified. 
0.0859 
Natural 
stuff- 0 
- Purified with ammonium car- 
1 bonate solution & nitric acid. 
0.0863 
The amount of the sample to be taken for analysis must be determined 
according to its galaelan content. If its content is below 16% on dry matter 
basis, 3 grams can be taken but if more galactan is contained, then a corre- 
spondingly smaller amount of the substance must be used, as otherwise the 
mucic acid is liable to crystallize out before the filtration. On the other 
hand, if the amount of galactan is insignificant, and below 0.8^6, the fil- 
trate should be evaporated down into one-fifth its original volume, and allow- 
ed to stand several days if necessary; otherwise the mucic acid may fail to 
crystallize even after long standing and it may lead to an erroneous con- 
clusion. 
Comparison of the Results. 
The tables given below show the results obtained by the provisional as 
I) Cotyledon of soy-bean 
2) Cotyledon of 2 weeks seedling. 
