BRIEFER ARTICLES. 
PHYSIOLOGICAL NOTES. I. 
1. Soja beans for imbibition experiments. 
No sEEDs, unless they have been killed, are suitable for the demon- 
stration of imbibition except when the experiment is to run for a short 
time, as for a single day. But for such brief experiments — and they 
are as good as longer ones — the Soja beans are an especially interest- 
ing subject, because of their pronounced change of shape in swelling. 
The three diameters may be designated as D, the longest one, passing 
between the cotyledons, at a right angle with D’, which also passes 
between the cotyledons, but through the hilum, and D", which passes 
through the cotyledons. The average lengths of these in ten air- 
dry beans were: D, 0.30734 inch; D’, 0.28061 inch; D", 0.22583 
inch. After soaking twenty-four hours in distilled water at 14° C., 
the measurements were: D, 0.53708 inch; D’, 0.34193 inch; D", 
0.2651 inch. The increase had been: D, 74.75 per cent., D’, 21.85 
per cent., D", 17.39 per cent. I have never seen a change in shape 
comparable to this in the swelling of any other hard and solid sub- 
stances. The swelling at first is more uniform in all directions, so far 
that D" is occasionally greater when imbibition is a little over half 
complete than when it is finished (!), though the seed coats are not 
wrinkled when this occurs. The increase in bulk of these beans was 
very nearly 150 per cent., while the increase in weight was only 133 
Per cent. (the dry beans are very heavy). 
orking on the micellar hypothesis, we expect the power to con- 
heat in any direction to vary somewhat inversely to the power 
to absorb water - since the greatest swelling will be in the direction of 
va least axes of the micellae, where the proportion of surface to mass 
'S 8teatest, while heat is conducted most easily lengthwise of the micel- 
lae, in the direction of fewest breaks. Thus heat travels most readily 
lengthwise in wood, at a right angle to the line of greatest swelling. 
i it with these beans by the usual method, melting a very thin 
yer of paraffin on the surface, and sticking a hot needle in the 
1900] 
duct 
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