( 974 ) 
quite the same as that described by Ropewarp for amylum tritici’). 
Petroleumether (b. p. 80°—100° C.) was used as pyknometer-liquid 
which, as proved by check experiments, is not imbibed by the sub- 
stances employed. Of the lines determined only those for casein are 
given; with the other substances I obtained lines of the same shape. 
I also had reproduced on the illustration the results of Roprwarp 
with amylum tritici, although these experiments are not of great worth 
for the purpose of comparison with liquids, owing to the presence 
of layers in the starch granules (in amylum tritici, however, this 
alternate construction shows but faintly). In both cases the curve 
exhibits the form of an hyperbola. E 
In the three miscible substances were found volume contraction 
lines of the same form *); these curves also make the impression of 
being hyperbolas *). In the volume contraction we also find, therefore, 
the same analogy in the quantitative laws of the two phenomena. 
d. Connection between heat of imbibition and contraction of volume. 
If the volume contraction c of a swelling substance is divided by 
the heat of imbibition (JV) at the same degree of imbibition, figures 
are obtained which, in the different imbibing bodies, are in the 
same order of magnitude. As this relation often changes considerably 
with the degre> of imbibition, I caleulated -- in order to obtain 
3 rarr AS 
comparable values — the quotient = for very small 2’s:(2 — 0). 
In the three miscible liquids this quotient has also values which 
agree very well. 
What is now particularly striking is that this order of magnitude 
is the same with miscible and with swelling substances. The subjoined 
1=0 
c 
table gives the value of ey 
PASEN Piste, cco en ea Ogee TED sulphuric acid . 0.0020 
aay lun, sibren 400 ee SALON orthophosph. acid. 0.0010 
woody fibres (crude fibre determ.) 0.0021 glycerin. . . 0.0024 
1) Zeitschr. f. physical. Chem. 24, 201 —202. 
2) Calculated from experiments of Domke for sulphuric acid (Lanpott, BORNSTEIN, 
Meyennorrer'’s Tabellen 3e Ed., pg. 328), of Scuirr for phosphoric acid (Lieb. 
Ann. 87, pg. 192); of Lenz for glycerin (Lunez’s Techn. Unters. Meth. HI, pg. 160). 
8) THomson had pointed already out in 1883, that the volume contractions of 
acetic acid by mixing with water follow a hyperbola. : 
