( 966 ) 
Will not only agree qualitatively but the quantitative lavs of the tivo 
phenomena will probably he the same. 
Lxperimental research as to the analogy in the quantitative 
huvs of the two phenomena. 
Whatever value one likes to attach to the theory of imbibition 
advanced, it leads in any case to a thesis which ean be controlled 
experimentally.  L have, therefore, instituted a comparative research 
as to the quantitative laws of imbibition in a number of amorphous 
swelling bodies and as to the miseibility in a number of comparable 
miscible substances; as such [ have chosen three liquids, whieh like 
imbibing bodies are practically non-volatile and can like these absorb 
large quantities of water, namely sulphurie acid, glycerin and ortho- 
phosphoric acid. 
In the case of a number of amorphous swelling substances, I 
determined, experimentally, the quantitative relations according to 
Which the heat of imbibition, the water vapour pressure and the 
volume contraction depend on the degree of imbibition; the results 
obtained were represented graphically. In a few cases 1 could make 
use Of measurements executed by other investigators. 
Afterwards, I did the same with the three miscible liquids. For 
the greater part [T could make use here of measurements already 
‘arried out by previous investigators for other purposes. But the 
water vapour pressures of glycerin- and phosphoric acid-mixtures 
had to be determined by myself and the heat generated on mixing 
glyeerin and water was measured in a series of experiments carried 
out jointly by myself and Mr. J. J. P. Varrron. . 
When choosing the swelling substances investigated, | have been 
careful to avoid unnecessary complications. For instance, such sub- 
stances as amylum in which layers rich in moisture occur alternately 
with layers poor in moisture do not seem to me suitable for the 
research ; for each of these layers has a different imbibition power 
and the phenomenon observed is composed of the sum of numerous 
elementary phenomena which obey different laws. A fortior7 intricate 
products such as peas or Laminaria in which all kinds of elements 
as cell walls, cell nuclei, starch granules etc. are adjacent to each 
other are quite out of the question. I have also avoided using sub- 
1) Experiments of Biscuit, van BemMeLen among others suggest that in some 
swelling substances there may be complications, so that the water absorption is 
not only due to swelling, but partly to capillarity (in preformed pores). In such 
cases we might expect to find different quantitative laws, 
