332 Scientific Proceedings, Royal Dublin Society. 
and a little behind NaCl. ‘The viscosity of the NaCl solution will 
be about 1:0435; that of the MgSO, about 1:0042; and that of 
the MgCl, about 1: 01. 
Many phenomena find explanation in the effects which appear 
involved in the foregoing experiments. Thusthe well-known greater 
compactness of marine sediments is probably referable to the 
coagulative or flocculative effects arising in the electric activity 
of the ions in discharging or neutralising the repulsive electric 
layers. It is probable, too, that minute traces of metallic ions 
are carried down with the sediments (Linder and Picton). Of 
such those of the higher valencies would form the chief part. The 
absence of the ions of higher valency—manganese and aluminium 
—from the sea, and their precipitation in the sediments, may 
wholly or in part be due to the processes we have here briefly con- 
sidered. This must not be forgotten in considering the inner 
mechanism of sedimentation. 
Again, this abstraction of the active ions must influence the 
alkalinity of the sea, reducing this somewhat where it receives the 
sediments of the rivers. 
