350 
ing granite: 88,000 grains of this water gave a solid residue 
of 10-50 grains; containing organic matter, 2°47 grains. 
The complete analysis of this solid material showed it to 
contain per cent.— 
Organic matter (crenic and apocrenicacids),. 23°30 
Co DeICMeRE Se otto ee ee ne ee ee 
Munaticacids: {IN LOLS. AO Ssgegg 
Salpluric’acids! 6D) 20. 6. agape eng energ4 
Sia sadtieiesiols 92) a slo GES Goh o WR 
Iimesaee. ted iui tie A. cotedocicesest Gene 
Mapnciag bani oil Pk cert [kiltip oan EE 
Pts: an Oe, ae ee | ee PPM, mee STS 
STE ee. Se en henner hS 
otis) Pr ere ee aw eee mee eS 
100-00 
The large quantity of muriatic acid in this water is of course 
present as chloride of sodium, derived from the vapours carried 
over to those mountains from the immediately adjoining sea. 
This 17-99 of muriatic acid takes, therefore, 15-28 of soda to 
form common salt. The state of combination in which the 
sulphuric acid may have been in is not so easily assigned; but 
even if we allocate to it the strongest alkalies, there will still 
remain a large quantity, about 12°16 per cent. of soda, which 
must have been combined with the silica, and with the organic 
acids. 
The characteristic feature of those waters, which may be 
considered as the types of those flowing down the flanks of 
the granite hills south of Dublin, is the presence of consider- 
able quantities of alkaline silicates, principally silicate of soda. 
This might be expected, as it verifies the mode of decomposi- 
tion of granitic rocks, and the deposition of china clays, sug- 
gested by Brogniart and others, but the instances in which the 
waters of such localities have been accurately examined, and the 
actual removal therein of the alkalies and silica of the felspa- 
