(978) 
talline polysaccharide, amylodextrin, which had been prepared in two 
different ways. The first specimen was made according to the method 
proposed by NAGrni') and agreed entirely with the description given 
by that author of the substance; I am indebted for this substance to 
Prof. H. P. Wissman, who had it prepared for me by one of his 
students under his supervision. The other sample was made according 
to the directions given by Prof. Artuor Meyer °) of Marburg and 
had been kindly presented to me by that author for these experiments. 
It still contained a trace of dextrin, but this was too trifling to be 
able to cause any significant changes in the form of the hygrometrie 
line. As seen in the illustration, in both samples of amylodextrin an 
S-shaped line having a continuous course was found *). 
Summarizing: The form of the hygrometric line was determined 
in the case of three crystalline albuminous substances and one erystal- 
line polysaccharide. This line had in all cases a continnous course, 
showed nowhere discontinuities as is the case with inorganic salts 
containing water of crystallisation; and had in all cases an S-shaped 
form; the lines of the various substances strongly resembled each other. 
And the remarkable fact appeared that the form of the hygrometric 
line is the same in the ease of swelling crystals as in that of imbibing 
amorphous substances. 
Comparison of swelling (imbibing) crystals with mived erystats. 
Let us now ask ourselves whether this behaviour is in harmony 
with the hypothesis advanced that swelling should depend on the 
formation of a solid solution of water in the imbibing body. 
Solid solutions in the erystalline condition are called mixed crystals. 
The said theory applied to swelling crystals therefore runs: Crystals 
when swelling form mived crystals with water. 
For our knowledge of mixed crystals we are chiefly indebted to 
the researches of the physico-chemists during the last twenty-five 
years. The pioneer work has been carried out chiefly by O. LrHMANN, 
VETGERS, VAN ’r Horr and Bakuuis RoozeBoom. And so numerous 
1, Lieb. Ann. 173, p. 218—227 (1874); for the description of the erystals 
see in particular p. 223. Also compare Brown and Morris Journ Chem. Soc. 55, 
p. 449 (1889). 
2) Untersuchungen über die Stärkekörner, Jena 1895. 
3) 1 am still engaged upon a crystalline lipoide, protagon, and a crystalline 
globulin, the edestin from hempseeds. The results will be communicated in the 
more extensive publication. 
