418 
ACKROYD : ON THE CIRCULATION OF SALT. 
VIII. No. 448, p. 446, October 1901). It can be best shown here 
by reference to and explanation of the Elton Lake. The waters of 
this lake vary in composition, becoming more concentrated as the 
year advances. The seasonal change is exhibited in the following 
analyses :— 
In Spring j In Sunnner j In Autumn ^ 
(Gobel). (Knhuann). I (Rose). | 
Sodium chloride, NaCl 
Magnesium chloride, MgCl., 
Potassium chloride, KCl . . . 
Calcium chloride, CaCl., ... 
Potassium sulphate, K.^SO^ 
Magnesium sulphate, Mg.SO+ 
Water 
131 
lOo 
0-2 
l'(5 
r4-4 
99 -8 
7-4 
l()-8 
0-04 
2-20 
78 •.-)() 
99-44 
3-8 
19-7 
0-2 
.V3 
70-8 
99-8 
The two main bodies in solution are magnesium chloride and 
sodium chloride, and as concentration proceeds on the approach 
of autumn the former increases and the latter decreases in amount. 
Regarding the Elton Lake as a saturated solution we may plot these 
results along with the fact that a saturated solution of common salt 
with no magnesium chloride in it holds about 2(r5 per cent, of sodium 
chloride at normal temperature. We get the compound solubility 
curve as in Plate LXIX., fig. 4. 
It follows that solutions containing less than 1 0 per cent, of mag- 
nesium chloride when saturated with common salt will give analytical 
data which, upon co-ordination, will fall approximately on the curve. 
This I have proved. 
There is nothing anomalous therefore in the differences one 
observes between different lakes any more than there is in the seasonal 
differences existing in the Elton Lake itself. It is very largely a 
question of the amount of one body in solution being conditioned 
by the amount of another that there may be, to which of course 
must be added the geological nature of the gathering-ground supply- 
ing any particular lake. The Great Salt Lake, with a minimum 
quantity of magnesium chloride, may have a maximum quantity 
