650 Professor T. E, Thorpe [Marcli d, 



becomes more mobile wlieu subjected to pressure : in other words, its 

 viscosity is lowered by pressure. This is a very striking fact, and 

 so far as observation has gone it is without a parallel. Benzene, 

 ether, liquid carbon dioxide, all become more viscous under the 



Fig. 3.— Viscosity of Water between 0° and 100°. 



influence of great pressure. Now Professor Eontgen has pointed out 

 that thesie " anomalies " may be explained on the assumption that 

 water at ordinary temperatures is an aggregation of two distinct 

 kinds of molecules, one of which has the properties we associate with 



