70 
F. STOWARD, D.SC. '. 
The Absorption of Water by Tubers. 
A number of experiments were carried out with two 
varieties of tuber, one (a) being a thick, red skinned, and the 
other ( b ) a thin, white skinned tuber. In each case a third 
series (c) of peeled tubers was established. In each ex- 
periment definite numbers of either intact unsprouted tubers, 
or peeled tubers, were selected, weighed, steeped in water 
for ten hours, and after drying superficially were at once 
re-weighed. The data give in the table beneath represent 
the percentage of moisture absorbed : — 
Table IV. 
Percentages of water absorbed by intact tubers, 
and peeled tubers. 
1 0-29% °-4 I % 6-33% 
2 0.55 0.55 
3 o.2i 0.79 7.72 
These results, although showing a considerable range 
of variation, evidence the fact that although water is not 
freely absorbed by intact tubers, it is by peeled tubers. 
From the fact that after a few hours’ exposure in an airy 
space this excess moisture readily evaporates from intact 
tubers, it is safe to conclude that when the duration of 
steeping does not exceed ten hours the bulk ol the water 
taken up is solely absorbed by the skin, and that very 
little if any moisture penetrates into the starchy tissue of 
the tuber. 
The Steeping of Tubers in Brine and other 
Salt Solutions. 
In the preceding section the evidence advanced points 
to the fact that water does not readily penetrate through 
the skin of the steeped tuber. 
It appeared desirable to investigate the behaviour of 
tubers in regard to the apparent impermeability of their 
skins by steeping intact mature tubers in solutions of common 
salt (NaCl). Undamaged tubers were therefore steeped in 
solutions of common salt of 10% and 15% strengths for 
eight days. During the progress of these experiments 
samples of the brines were removed and determinations 
made of their salt contents. An example of one of these 
trials selected from a number of closely similar and similarly 
conducted experiments is given below : — 
