35 
and sulphate, and also the chemical nature of the plankton 
but I hope to return to this work next summer, and take 
up these matters. 
10.—Concuuston. 
On considering the results which I have so far deter- 
mined it seems that the waters of the Irish Sea consist of 
two types :—(?) that at the Isle of Man and in the deeper 
parts around, and (27) that along the Lancashire coast. 
The former appears to be very little affected by tides, and 
to have the salinity of ocean water, whilst the latter alters 
very much both according to the tide and to the amount of 
water poured out of the Mersey and other rivers. At low 
tide the salinity as far out as the N.W. lightship is low, 
whilst at high tide the water at the Liverpool Landing 
Stage contains more salt than some other less estuarine 
localities. 
The alkalinity seems very irregular. It is lower round 
the coasts of the Isle of Man than in some of the more open 
parts, as one might expect, but its height in some places in 
Liverpool Bay is remarkable. Why in the Crosby Channel 
almost at low tide it should be higher than at the Landing 
Stage or the Isle of Man at high tide is not obvious; or 
again, why the highest value is obtained in the Rock 
Channel off New Brighton. 
No sections of the water of the Irish Sea can yet be given 
as too few observations have been made, but the following 
table * is a summary of all the results, and will give a fair 
idea of the composition of the water in the different parts. 
* The .values now given supersede those in my table printed in the 
L.M.B.C Annual Report. That table was incomplete and only approxi- 
mate, as all the results had not then been worked out. 
