Under these conditions a wide variety of physical and chemical agents cause changes in the permeability of the tissue to water, which are referable to the cells of the part; these agents include increased temperature, anoxia, ethyl alcohol, chloroform, bacteria, and bacterial products.

With heating of liver tissue increased permeability reaches a maximum at 50 to 52°C. and is lost at 55° when heat coagulation has occurred.

Permeability of liver cells has increased in the presence of cultures of colon bacilli, of culture filtrate, of killed typhoid bacilli and apparently of diphtheria toxin. Somatic antigen from paradysentery bacilli has caused increased permeability of liver cells.

The experiments indicate that a substance formed by normal metabolism, namely urea, may, under some conditions, increase the permeability of liver cells.