314 



EEPOET — 1879. 



They also differ in composition from concretions deposited at the pit bottom in 

 the cold, which show only 47*71 per cent, of Fe 2 3 . 



Observations made to ascertain the Temperature at which the deposit and turbidity 



take place. 



The action of this mineral water is destructive to all iron work with which it 

 comes in contact. The amount of iron dissolved by samples of the water in the 

 cold being as follows : — 



July, 1868—7,000 fluid grains = 1 lb. of the water dissolved 1-85 grain of iron 



during one month. 

 Feb., 1876—3,500 fluid grains = lib. of the water (collected during a dry season) 



dissolved 2-91 grains of iron in eight months. 

 July, 1876 — 3,500 fluid grains = \Vo. of the water (collected during a dry season) 



dissolved 4-73 grains of iron in eight months. 



Reaction of the water with litmus at the conclusion of these experiments only 

 faintly acid. 



Quantities of iron pyrites are found in the coal strata of this neighbourhood, 

 and account for the large quantities of sulphates often found in these colliery 

 waters. 



The water during jfiood seasons required (as an average of five determinations) 

 an addition of 10-48 grains of anhydrous Na 2 per gallon, before an alkaline reaction 

 was obtainable, and during dry seasons (as an average of three determinations) an 

 addition of 17*35 grains of anhydrous Na 2 per gallon. This amount of alkali 

 does not all correspond to free acid, as the sulphate of iron would also neutralise 

 soda. 



Determinations of the total inorganic constituents were made at the dates and with 

 the results as below. — Results in grains per gallon. 



The sulphates, a very important element in the composition of this water, were 

 determined as per following results. An average of six estimations of the total 

 sulphates (results calculated as S0 3 ), extending from 1865 to 1876, made during — 

 Dry seasons — giving H5-41 grains per gallon of S0 3 - 



An average of eight estimations, extending over the same period of time, but 

 made during 



Rainy seasons— gave 67 - 62 grains per gallon of SO s . 



A fact worthy of notice in course of these analyses is the steady and large 

 increase in the amount of the sulphates, from the commencement of these observa- 

 tions in 1865 to 1876. 



The same result is also noticeable on reference to the total amounts of inorganic 

 matter, which show a great increase in quantity during the latter part of the 

 time. 



Now why this increase in the total sulphates and total matters in solution 

 should take place, it is not easy to say. It may be owing to the fact of the increased 

 length and area of the workings in the colliery, as undoubtedly there is more bulk 

 of water to contend with now than formerly on this account ; but why the mineral 



