KiNAHAN — On the Clearing of Peaty Waters. 455 



"When mixed with clear and colourless water it forms a very dirty 

 turbid solution ; after some time this clears considerably, but the liquid 

 always retains a peculiar turbidity, which is very like the turbidity 

 produced in a peaty water when an insufficiency of the clearing agent 

 has been added. It was found that the turbidity could be removed by 

 adding a small quantity of the next specimen to be described. 



This blue clay seems to have been originally a red clay, very similar 

 to that next mentioned (specimen/); its present condition being due to 

 percolating peaty waters. This is inferred from the following observa- 

 tions : — 1st. A similar blue clay overlies specimen /, as seen in the banks 

 along the Mucklagh brook, the passage from one to the other being 

 gradual ; red stones and patches of red clay are seen occurring in this 

 overlying clay. 2nd. The residues left by both specimens, after digest- 

 ing in hydrochloric acid, are alike. 3rd. The percentage of insoluble 

 matter in specimen S is greater than in specimen /, the more 

 soluble portions, iron and alumina, having been probably removed by 

 percolating waters. 



Specimen I. — A brick red clay from one of the tributaries of the 

 Mucklagh brook, where it occurs under a blue clay like the last 

 specimen, a gradual passage from one to the other being distinctly 

 visible. It yields an insoluble residue similar to the last, but the 

 percentage of soluble matter is greater. 



Insoluble in hydrochloric acid, 72'41 per sent. 

 Perric oxide, 9-70 ,, 



Alumina, 9-41 ,, 



It yields with water a perfectly clear solution when the fine 

 particles have subsided ; which, however, is not for some considerable 

 time. 



This specimen acts as a very efficient decolouriser of peaty waters. 

 When mixed with a peaty water the fine particles remaining in sus- 

 pension give the liquid a brick-red colour ; when they subside the 

 peaty water is found to be quite decolourised, if sufficient (about 

 20 grammes to 1000 cc.) has been added. 



With an insufficiency of clay the usual changes are observed. 



Specimen K. — A whitish sandy clay, from the banks of the Cara- 

 way stick brook, where it occurs in an ancient moraine above the falls; 

 it was some of this specimen that was mixed with the waters of this 

 brook, as mentioned in the field notes, p. 451, mpra. 



Insoluble in hydrochloric acid, 93-91 per cent. 



Ferric oxide, 1*60 ,, 



Alumina, 2* 17 ,, 



This specimen, even in large quantities, produces very little altera- 

 tion in peaty water ; when added, very little remains in suspension for 

 any length of time. 



