175 
1888-89.] Mr A. Johnstone on Action of Sea- Water. 
liberated silica being dropped in the insoluble or almost insoluble 
silicon dioxide condition. 
Perhaps the following equation states the changes correctly : — 
gives 
Pure Steatite, 
and 
Water, and 
Sodium Chloride. 
4Mg"Si0 B .Si0 2 
+ 
8H 2 0 + 
8NaCl 
Sodium Silicate, 
and 
Magnesium Chloride, 
and Silica. 
4Na 2 Si0 3 .8H 2 0 
+ 
4MgCl 2 
+ Si0 2 
Magnesium, as all are aware, exists chiefly in sea-water in the 
form of chloride. 
White pure talc is decomposed at about the same rate as pure 
steatite. The common green variety, however, owing to the 
presence of ferrous silicate in fair quantity, is more readily altered. 
One thing must certainly be remembered distinctly, and that is, 
that the process of decomposition which is undoubtedly promoted 
in pure magnesium silicates by sodium chloride waters, does not 
progress at a rate which from a human standpoint can be considered 
at all rapid. 
Deductive Evidence of a Uterine Nerve Centre, and of 
the Location of such in the Medulla Oblongata. 
By James Oliver, M.D., F.R.S.E. 
(Read February 18, 1889.) 
At no time does Nature furnish us with any proof of bodies 
existing in a state of absolute rest. The whole molecular world, 
organic as well as inorganic, is, as far as we can ascertain, in con- 
stant motion. In consequence of this well-established principle, 
every function of the body may rightly be considered as resulting 
from a change in the molecular state of the organ manifesting such, 
and as being the expression of a correlative variation occurring in 
its representative nerve centre. Through the agency of long con- 
tinuance the visceral disturbances are now carried on in a somewhat 
automatic manner, and fail to excite any feeling of their existence, 
although they may at one time, in the evolution of higher organisa- 
tion, have produced a conscious sensation. In no organ do we find 
these revelations so well depicted as in the uterus. In every 
