360 MR. T. CARNELLEY ON AN ANALYSIS OF 



1,000,000, the reason being that the quantity of sodium 

 present was only very small, so that the traces of it also 

 contained in the reagents had an appreciable effect, though 

 they were as pure as could be obtained. The results got 

 for the potassium, however, agreed very nearly. 



(7) The lead was determined by the method given in 

 Wanklyn & Chapman's ' Water Analysis/ as were also the 

 ammonium, albumenoid ammonia, and nitric acid. 



From a comparison of the above two analyses it is evi- 

 dent that, between September 1871 and September 1874, 

 the composition of the water has varied considerably ; and 

 though the author has not had an opportunity of seeing 

 the analysis made in 1844 by Waldie, yet from Dr. 

 HassalFs report, given in the above-mentioned pamphlet, 

 it would seem that the results there given also vary much 

 from those obtained by Waldie. The quantity of iron 

 appears to have greatly diminished, while, with the excep- 

 tion of Si0 2 and chlorine, that of the other constituents 

 occurring in larger quantities has considerably increased. 

 A determination of the iron, made last February, gave 

 1575*4 parts per 1,000,000, though in this case the deter- 

 mination was not made till after the water had been col- 

 lected some days. From this it would seem that the iron 

 is gradually diminishing in quantity. The result, how- 

 ever, obtained by Waldie is very nearly the same as that 

 got by Hassall. 



From the analysis it will be seen that the Trefriw water 

 is peculiar, as already mentioned, on account of the large 

 quantity of sulphate of iron which it holds in solution ; 

 there being, so far as the author has been able to learn, 

 no spring in the United Kingdom, and perhaps not even 

 on the Continent, which contains it in any thing approach- 

 ing to the same amount ■ while there are only a few springs 

 known which contain it even in a notable quantity, the 

 analyses of which have been described. The water is also 



