46 BURRELL : THE COMPOSITION OF SOME MALIIAM WATERS. 
In I. tlie quantities of the different constituents are given, 
in II. the acids and bases are combined together in the usual 
manner, and in III. the previous analyses are given for reference. 
In II. a comparison of the Tarn water with that issuing 
from Aire Head Spring shows that the underground course has 
effected a considerable change in its composition ; the calcium 
carbonate rising from 4 grains to 9*77 grains, or an increase of 
nearly two and a half times, the magnesium carbonate from 
0-35 to 0-84, practically the same ratio, whilst there is a slight 
diminution in the calcium sulphate. No nitrates could be detected 
in the Tarn water, whereas the Aire Head water contains an 
appreciable quantity. 
The experiments carried out by the Society during the 
summer of 1899 proved conclusively that the Smelt Mill stream 
issued at Malham Cove, but as Tate remarks, "the volume of 
the Smelt Mill Syke is not a twentieth that of the Cove 
stream,"* and it is therefore obvious that the Cove stream is 
fed from other sources. The comparison of the analysis of the 
Smelt Mill water with that from the Cove, leads to the sup- 
position that in the latter there is a large volume of a much 
softer water. 
In the Cove water the proportions of calcium and magnesium 
carbonates, the calcium sulphate and the total dissolved matter 
are all slightly less than in the Smelt Mill water. If the Smelt 
Mill water could be obtained free from admixture with other 
waters as it issues from its underground course, there is not the 
slightest doubt that there would be a considerable increase in 
the quantities of calcium and magnesium carbonate. 
It will be noticed that the Cove Avater contains nitrates, 
though none are present in the Smelt Mill water. The con- 
ditions favourable for the development of the nitrifying organism 
are a base such as calcium carbonate, traces of phosphates, free 
oxygen and darkness, all of which are fulfilled during the under- 
ground courses of the Tarn and Smelt Mill waters. 
* Proceedings Yorkshire Geological and Polytechnic Society, Vol. VII. , 
page 184. 1878. 
