OF THE GASES OP THE KING'S BATH SPRING. 7 



between the quantity at one minute and another appearing to be as 53'3 to 21*5 

 cubic inches, or as 5 to 2. So that the quantity evolved from the central orifice 

 seems to be about one seventh of that from the area from which the gas was before 

 collected. 



Upon reviewing the aggregate of the observations above detailed, I cannot bring 

 myself to believe, that the gas at present disengaged in a given time from the King's 

 Bath is to be regarded as invariable in quantity ; for the diiferences between the results 

 obtained on one day and another are too considerable to be referred to errors of mani- 

 pulation, or to the escape of the gas in a greater or less degree from other avenues. 

 Besides, there will be seen, by referring to the annexed Table, a kind of flux and 

 reflux in the quantities obtained ; that of September 17th exceeding the mean by no 

 less than seventeen cubic inches, those of the 18th, 19th, 20th, 21st, 23rd falling short 

 of it by variable quantities ; that of the 24th exceeding it again ; on the 25th and 

 26th approaching it very nearly ; on the 27th, and again the next time of observing-, 

 namely on October 2nd, exceeding the mean ; from thence till the middle of the 5th 

 falling short of it a little, then till the 9th exceeding the mean, on the 17th falling- 

 short of it again, but on the 18th again rising somewhat beyond the average. 



If, then, a variation in the quantity of gas emitted seems to be fairly substantiated 

 by the observations I have recorded, it becomes a subject for inquiry, to what cause 

 this irregularity may be ascribed. 



I at first imagined, that its emission might be in some degree controlled by atmo- 

 spheric pressure ; but the general tenor of the observations seems to dispell this notion, 

 or at least to show, that there are other causes by which its flow is in a greater degree 

 affected. Neither do the other conditions of the atmosphere noticed in the Table 

 appear to exert any appreciable influence upon the current of gas, though, as the 

 weather during the time I spent at Bath was in general fine, and during a large 

 portion of the time remarkably steady for the season, it were to be wished that some 

 gentleman resident on the spot would avail himself of the opportunities that might 

 present themselves for examining the spring under a greater variety of circumstances ; 

 especially, as it has been vaguely stated with regard to some other hot springs, on the 

 authority of casual observers, that the evolution of gas is greatest during storms and 

 gales of wind*. 



With regard to the quality of the gases given off*, I have but little to add to what 

 had been before determined. In the air I collected, oxygen certainly was present, 

 as indeed Sir G. Gibbes had already ascertained to be the case, by the test of nitrous 

 gas. Phosphorus heated in a bent tube with a measured portion of the air causes a 

 diminution in its volume, which in almost all my trials amounted so nearly to 

 1 -25 per cent., that I set down the proportion of those two gases one to the other as 

 probably constant; and if we grant that nitrogen obtains an increase of bulk 

 amounting to 2-5 per cent, by phosphorus vapour, I cannot be far wrong in reckoning 



* The same thing has been noticed with regard to volcanos. See Scrope's Considerations on Volcanos, p. 7. 



