402 
ACKPvOYD : OX THE CIRCULATION' OF SALT. 
It will be convenient to speak of this salt as " sea-salt," in contra- 
distinction to such as may he derived from the earth by solvent denu- 
dation, which will be referred to as " earth-salt,"' and the proportionate 
amount of the sodium compound will be indicated in this paper by 
the chlorine figure. 
Circulation of Sea-Salt. 
The conditions obtaining in the Widdop area are of more than 
ordinary scientific interest, and 1 have made an experimental in- 
vestigation . of them during the winter 1000-1, whicli has been com- 
municated to the Chemical Society of London.* From November 
12th to February 18th weekly chlorine determinations were made 
of the reservoir water, of the water in a rain-gauge kept close by, 
and of rain-gauge water on four other gathering grounds some miles 
to the east of Widdop, viz.. Walshaw Dean, Midgley, Warley, and 
Ovenden Moors, besides daily tests of rain-gauge water from Belle 
Yue, in the town of Halifax. The area under investigation, with 
its position in England and the relative positions of the rain-gauges» 
are given in Plate LXYI. The results of the weekly tests are 
shown in the following table : — 
Chlorine, Parts per 100,000 in Rain-Gauge Water. 
Height ahove 
sea level. 
Widddp . 
Reservoir. 
Widdop. 
i,or.{) ft. 
Walshaw 
Deiiii. 
1,380 ft. 
Midfiley 
Moor. 
1,:;50 ft. 
Warley 
Moor. 
l,:j-25 ft. 
Ovenden 
Moor. 
1,375 ft. 
November 
,2 
1-2 
0-8 
0-3 
11 
1-2 
1-3 
19 
11 
0-7 
0-7 
0-4.-) 
0--) 
26 
1-0 
i-o 
OGo 
1%-) 
0f> 
0-8 
December 
8 
l(> 
0-5 
1 Of) 
0-7 . 
0-9 
0-7 
10 
0-2 
()•« 
0(; 
O-f) 
0-.-) 
17 
11 
0-2 
0-8 
0-7 
0-8 
0-7 
•24 
ll.-) 
3 '3 
2r)r) 
31 
21 
2-45 
31 
1 1 
11 
0-9 
1-6 
11 
0-9 
January 
1-2 
1 2 
Ooo 
21 
1-8 
U 
1-8 
e?) 
2-75 
2oo 
2-4 
31 
21 
1 -I-y 
0-8o 
10 
11 
0-7") 
28 
1 -20 
1 -7') 
l-(> 
1-8 
1-9 
1-4 
February 
4 
(?) 1-4 
0-8 
10 
2-7 
1-2 
1-4 
11 
1 "2 
1-75 
1-6 
2-45 
2 2 
1-8 
18 
1 -3 
Average 
1-188 
1-50 
* Trans. Chem. Soe., Vol. 79, p. 673. 
