52 Arber—On the Effect of Salts on the Assimilation 
development. A study of the composition of sea water is 
therefore important in itself. 
Two analyses of British sea water may be quoted. Analysis 
A was made by Thorpe and Moreton 1 of water collected 
from the Irish Sea in winter (Sp. Gr. 1-02721 at o°). Analysis 
B is from water from the Bristol Channel (Sp. Gr. 1*0274 
at 15-5° C.) 2 * 
The form of these analyses has been altered here in order 
to bring the salts into order of their percentages. 
A 
In 1000 parts . 
Per Cent , j 
B 
Per Cent . 
Water . . 
. 96614054 
== 
96-614 
96.474 
1 NaCl . . 
26.43918 
= 
2-644 
2.706 
2 MgCl 2 . . 
3-i5 o8 3 
= 
•315 
•367 
3 Mg S0 4 . . 
. 2-06608 
= 
.207 ! 
.230 
4 CaS0 4 . . 
I *33 I 5 8 
= 
•133 
.141 
5 KC1 . . . 
. 0.74619 
= 
•075 ■ 
.077 
6 Mg Br 2 . . 
0-07052 
= 
6 
0 
*<r 
•003 
7 CaC0 3 . , 
0-04754 
= 
-005 
6 
0 
00 
Fe C0 3 . . 
0.00503 
Mg(N0 3 ) 2 . 
. 0-00207 
NH 4 C1 . . 
0-00044 
Traces of MgC0 3 , Li Cl, SiO a 
In the present paper it is proposed to deal with the five 
principal salts in sea water ; the three chlorides (NaCl, Mg Cl 2 , 
and K Cl), and the two sulphates (Mg S 0 4 and Ca S 0 4 ). In 
a future communication I shall hope to give some account 
of the effect on carbon-assimilation of those salts which occur 
only as traces or in very small amounts in sea water. A brief 
resuml of the chief results obtained from both these series 
of experiments was given before the British Association at 
the recent Bradford meeting 3 . 
1 Thorpe and Moreton ; vide Thorpe, p. 141. 
2 Tilden (’89), p. 67. 3 Arber (’00). 
