44 
T. TADOKOBO. 
In order to get an idea of how large a part each of these factors plays in caus- 
ing the loss, we made the following experiment. 
A definite quantity of air dry stem is taken into flasks containing a 
definite quantity of canal water. To one series of flasks are added a few drops 
of formalin, to prevent the propagation of micro-organisms, while to the other 
series no formalin is added. Arrangments were made with filter paper or 
cotton to prevent the aerobic retting. The results of the experiment follow. 
Table £». 
Experiment. 
(16-21° C.) 
Loss due to the 
combined actions. 
Loss due to the extrac- 
tive power of water 
alone. 
Loss due to the extrac- 
tive power of water in 
% of that of com- 
bined actions. 
after 7 days 
10.2 % 
17.2 % 
5.7 % 
10.2 % 
56. % 
after 12 days 
59. % 
Generally, the extractive power of water is proportional to the qnantity 
and temperature of water, and' the duration of immersion. In experiments 
cited, the difference in results is caused solely by the difference of duration, 
as the amount and temperature of water wore kept as similar as possible in 
both series. It is to be noticed that the loss of the stem due to the extractive 
power of water alone is more than half of that due to the combined actions. 
The loss of the dry matter is a measurement of the retting grade and it 
is important for the fiber manufacture to increase the loss of the stem without 
injurious effects upon the qualities of fiber and tow production. 
If the production of finer tows and fibers are desired, the double retting 
is to be recommended, since they are more easily obtained from the well ret- 
ted stem than the incomplete one. The loss which is estimated practically 
in Hokkaido is smaller than that in Europe, this is probably owing to the in- 
complete change of water. 
From the above experiments, we may conclude as follows. 
1. In case the water is changed, the loss of weight in the total stem is 
about 18-19% but on the basis of the stem proper it amounts to about 15 .%. 
