ONE OF THE TREFRIW MINERAL WATERS. 



357 



for drinking. They differ considerably in the relative pro- 

 portions of their mineral constituents ; but it is only the 

 last named which is the subject of this paper. 



The water, which flows into a basin cut in the rock, is 

 said to be uniform in quantity, and issues at the rate of 

 about 40 gallons per hour. It is quite cold, its tempera- 

 ture varying only within very narrow limits. As it occurs 

 in the spring it is perfectly clear, bright, and colourless ; 

 but after a short exposure to the air it turns yellow, and 

 deposits flakes of ferric oxide. It has no smell, but pos- 

 sesses a strong aud very disagreeable inky taste. On 

 being shaken up in a closed bottle no disengagement of gas 

 takes place. It has a strongly acid reaction, and contains 

 neither free carbonic acid, carbonates, nor sulphides ; and 

 when first taken from the spring it is perfectly free from 

 ferric salts. 



Temperature of the external air 15*50. 



,, „ air at the spring 12-5 



„ ,, water ii'o 



Specific gravity at 17 C. 



Loss on ignition 



Precipitate formed on boiling 1 hour 



Iron , 



Aluminium 



Calcium 



Magnesium 



Potassium , 



Sodium 



Manganese , 



Lead 



Ammonium (NH 4 ) ..., 

 Albumenoid ammonia , 



Silica (Si0 2 ) 



Sulphuric acid (S0 4 ) , 



Chlorine 



Nitric acid (N0 3 ) 



Phosphoric acid (P0 4 ) , 



Total solid contents 



The residue dried at 3 1 o° C. 



I. 



1*00716 



parts per 

 1,000,000. 

 7217-5 

 32-8 



1507-0 



*33'3 

 271-3 

 134-1 



315 

 25-1 



trace 

 o-86 

 163 

 0-34 



49 8 5 - 3 

 ir8 

 91 

 2-45 



7370-78 

 7370-00 



II. 



1-00570 



parts per 

 1,000,000. 



2009-4 



112*4 



116-5 

 45 '4 



I5-3 

 trace 



149*0 



4512-0 



109 



6970-9 



