1085 
placed in the vapour very quickly and that the velocity of this process 
influences the work done. As Bancrorr says, this alleged explanation 
is not likely to satisfy anybody; moreover it can be refuted by 
arranging VON SCHROEDER’S imaginary experiment in a slightly different 
manner. Pour upon the gelatine (in equilibrium with vapour) as 
much water, as can be totally absorbed, and place the whole in 
saturated vapour; it will now lose weight, till the vapour equi- 
librium is reached again. In this way the excess work, in von 
SCHROEDER’S Opinion necessary ‘for taking the gelatine quickly out of 
the liquid, is eliminated. 
FREUNDLICH *) introduces special attracting forces of the surrounding 
liquid on the gel. As long as one does not enter into detail as to 
the nature of which these forces are, nor why they have so much 
influence especially with the gels, this explanation does not seem to 
be more than a circumscription of the facts, and we agree with 
Bancrort, who declares it to be “neither very clear, nor very 
convincing”. 
We must acknowledge, however, that we ourselves are not able to give 
a better. one. When looking for the directions, in which the solution might 
be sought, we find hysteresis, gravity, and capillary action. Hysteresis, 
of course, would do away with the possibility of a perpetuum mobile 
of the second kind; we should then have to assume, that every time 
slight changes are left in the gel, and that it would consequently 
be impossible to detect ad infinitum differences in water content, 
when the process of transferring the gel from liquid to vapour, and 
vice versa, is repeated. No fact, pointing in this direction, has 
however been found, neither by von SCHROEDER nor by us; but it 
may be, that the process has not been repeated often enough; of 
course, this is not a more fundamental explanation either. 
Concerning the influence of gravity, we wish to remark, that it 
might possibly explain the loss in the vapour, but never the-gain in 
the liquid. Moreover, von SCHROEDER made some experiments with 
regard to the influence of gravity, but with negative results. This 
would not, however, be a sufficient ground to deny the effect of 
gravity, since, as Bancrort justly remarks, the effect Se be too 
small for observation. 
When, at last, we try to ascribe the phenomenon to the action of 
capillary forces, we do not make more progress than FREUNDLICH, 
though in this direction perhaps success will be most probable. 
Path. Anat. and Inorg. Chem. Laboratories 
University of Amsterdam. . 
1) Kapillarchemie, p. 494—497. 
