BOTHAMLEY ! MINERAL WATERS OF ASKERN IN YORKSHIRE. 355 
of the sulphuric acid radical (S0 4 ) in grammes per litre in the four 
waters at various times of the year : — 
Mather 
Close. 
Charity. 
Terrace. 
Manor. 
1389. 
Sept. 27 and 28 
i Sulphuretted hydrogen 
\ Sulphuric acid (SOj ••• 
567 
0-7063 
34-8 
0 9660 
49 5 
0-6698 
37 3 
0 9490 
1890. 
July 12 
f Sulphuretted hydrogen 
[ Sulphuric acid (SO J ... 
55 0 
0 9093 
26 4 
1-1017 
54-0 
1-7697 
Nov. 1 
1891. 
Jan. 17 
$ Sulphuretted hydrogen 
/ Sulphuric acid (SO4) ... 
Sulphuretted hydrogen 
42-3 
0-7018 
22 5 
317 
0-9099 
23-6 
0-7978 
361 
0 9956 
April 18 
f Sulphuretted hydrogen 
\ Sulphuric acid (S0 4 ) ... 
49 6 
0-7023 
55-3 
07268 
219 
0 6359 
July 29 
Sulphuretted hydrogen 
52 0 
38 4 
46 2 
34-2 
It will be seen in the first place, that the volume of sulphuretted 
hydrogen varies in one and the same water with the time of year. 
This comes out very distinctly in the Mather Close water, which was 
the most frequently examined : — 
July. September. November. January. April. July. 
55 0 ... 567 ... 42 3 ... 225 ... 49 6 ... 520 
The proportion of this gas is lowest in mid-winter ; increases as the 
weather becomes warmer; attains a maximum in summer and autumn, 
and then again decreases as the weather becomes colder. At the same 
time it is clear that the quantity of sulphuretted hydrogen present in 
the waters from late spring to early autumn, or in other words, during 
the time for which they are chiefly used for medicinal purposes, is 
practically constant, and, moreover, varies but little from year to year. 
This is a point of considerable practical importance. 
Only indirect evidence can as yet be offered as to the origin of 
the sulphuretted hydrogen. The following facts are, however, im- 
portant in this connection : — The quantity of sulphuretted hydrogen 
varies in the different wells at the same time of the year, and varies 
in the same well at different times of the year, the variations being 
periodic and in close relation with the season of the year. It has no 
relation to the quantity of sulphates present in the waters, and its 
B 
