HUDLESTON AND DAVIS : EXCURSION. 
123 
chiefly of vegetable oiigin, locked up in the Yoredale Rocks. 
Hence it is not unreasonable to believe that the putrefactive 
distillation of such organic matter, acting very slowly and through 
long periods of time, effects more or less the complete deoxidiza- 
tion of the sulphates, and that to this we owe the quantity of 
sulphide present in the Harrogate waters. The considerable 
quantity of carburetted hydrogen and of nitrogen found by 
Hoffmann favour this view, which is much strengthened by the 
almost complete absence of oxygen, showing that the nitrogen 
present is due to organic decomposition. At the same time the 
very slight traces of phosphoric acid would show that this mainly 
arises from vegetable matter. 
EXOUESION ON THE 17TH JULY, AND FIVE FOLLOWING DAYS. 
Directors :-~W, H. HUDLESTON, F.G.S., ETC., President of 
the Geologists' Association^ London; AND JAMES W. DAVIS, 
F.G.S., ETC., Honorary Secretary of the Yorkshire Geological 
and Polytechnic Society. 
The London contingent arrived at Harrogate on Monday 
afternoon, and havings secured quarters at the Prospect Hotel, 
re-assembled wnth the other members of the party at the Old 
Sulphur Well. Here they tested the quality of the water for 
which the place is celebrated, and availed themselves of the per- 
mission wdiich was given to them to descend underneath the 
floor of the building to inspect the springs wdiich supply the pump- 
room above. The President of the Geological Association, London, 
who on this occasion was the director, offered a few remarks on 
the chemical composition of the water and of several other sulphur 
watei s of Harrogate. He was enabled to illustrate his observa- 
tions by means of a number of specimen tubes containing- the saline 
contents of one gallon of each of the various waters to be found 
in the town, and by this method the different volumes were at 
once perceived. These very interesting tubes had been prepared 
from evaporations conducted by Mr. Davis, chemist, of Harrogate. 
They are the property of theHarrogate Improvement Commission- 
