8 DR. DAUBENY ON THE QUANTITY AND QUALITY 



the oxygen at rather less than four parts, and the nitrogen as rather more than 96, 

 in the 100. This, however, is to be understood as only applying to the gas remain- 

 ing after having been agitated with a solution of potash ; for there is always present 

 a certain portion of carbonic acid, which on some occasions appeared to amount 

 nearly to what Mr. R. Phillips in his analysis has stated it at, namely at 4*5 per cent, 

 of the whole quantity. 



1 have at other times, however, found it to reach 8 or 9, and once even 13 per cent.; 

 so that I am forced to conclude this element in its composition to be of variable 

 amount. 



As, however, the quantity that escapes is only the excess over and above that which 

 the water itself holds in solution, the cause of its variation may perhaps be explained, 

 without imagining it an indication of any change in the nature or intensity of the 

 processes to which the heat of the springs is owing. 



The quantity of water which is discharged per minute has been calculated at 

 about 146 gallons, of which 126 gallons are received at the King's and Queen's Bath, 

 10 at the Cross Bath, and about 10 at what is called the Hot Bath. 



Now it is stated by Mr. Phillips, that every pint of the water contains 1*2 cubic 

 inch of carbonic acid; so that about 1400 cubic inches of carbonic acid are dis- 

 solved in the water, whilst the quantity that escapes may vary from about 12'3 to 360 

 cubic inches*. 



It is evident, therefore, that an increase in the supply of water from 146 to 150 

 gallons would occasion the whole of the gas to be absorbed, and that a difference of 

 only two gallons and a half in the amount of the water discharged would account 

 for the utmost variation in the quantity of carbonic acid, which I have ever detected 

 between one day and the next. 



Now, though the supply of water is remarkably uniform, I conceive, that so slight 

 a variation as that hinted at, might easily take place without its being observed-j^. 



It might be worth while to ascertain, whether the quantity of gas evolved bears any 

 relation, either to the temperature or the copiousness of the spring from which it 

 rises; and, so far as the thermal waters of this country are concerned, it would appear, 



* Mr. Walcker's analysis (Journal of Science for June 1829,) differs from the above, as he calculates only 

 0*95 of a cubic inch of carbonic acid in every pint of the water, or 7*6 cubic inches to the gallon. Even then, 

 however, 957*6 cubic inches of gas would be given off every minute by the spring, even if we do not count 

 any portion of that which exists in combination with the iron, lime, or alkalies, as derived from the interior of 

 the earth. The latter Mr. Walcker has stated at 1-62 cubic inch in every pint. 



t This, however, assumes, what perhaps will not be granted, namely, that the carbonic acid present in the 

 water is derived from the gas emitted from below, and not from the atmosphere. A cold spring from the lower 

 part of the city close to the Cross Bath, yielded me in the pint. 



Carbonic acid 0*90 



Nitrogen 0*64 



Oxygen 013 



Total I' 67 cubic inch. 



