88 Mr. West on a 



I apprehend no difference in medicinal power need be appre- 

 hended from the subtraction of one grain in the pint, of a neu- 

 tral sulphate, whatever be its base, when supplied by a corre- 

 sponding quantity of muriate. 



It seems, of itself, almost a convincing proof of the identity of 

 the general contents of the Old and the New Well, and of the 

 stratum whence they are derived, that at the period when the 

 latter was first examined, when no sulphuric acid could be de- 

 tected, it was wholly wanting in the former, in which, on pre- 

 vious occasions, it had been found. 



1 come now to consider the gaseous contents of these waters; 

 these agree in their nature, and nearly so in their total quan- 

 tity, with those found by other chemists. Dr. Garnett found 

 19 cubic inches of sulphuretted hydrogen in the gallon, the 

 greatest quantity which I obtained, even when large bubbles of 

 gas were rising through the water in the well, was under 17 

 inches. Dr. Scudamore found it in the Old Well about 14 

 inches ; the difference is not too great to impute to irregu- 

 larities in the production or absorption of the gas at the spring. 



The proportion of carbonic acid, found by me, differs much 

 from the statement of Dr. Garnett, and still more from that of 

 Dr. Scudamore. I may observe, that in about a dozen trials, 

 the proportion was almost constant. On this point, I think 

 some error must have crept into Dr. Scudamore's observations. 

 He deduced the quantities of the absorbable gases from the 

 weight of precipitate formed — a method which I tried, and 

 found very uncertain, and which must obviously be so, since 

 a loss or an increase of weight of one tenth of a grain in the 

 quantity which he employed, would give rise to an error of an 

 inch and one-third in the calculation for one gallon. Dr. Scuda- 

 more no where informs us, in a direct way, what was the total 

 quantity of gas obtained from a gallon of the water, and the 

 statement in p. 98 of his Treatise, 29.045, cannot possibly be 

 the result of the experiments he has described, since none of 

 the numbers agree with those obtained by calculation from his 

 data ; the proportion of unabsorbable gases, indeed, is but 

 ^bout two- thirds of that stated in p. 97. 



