Pond. — Notes on a Salt Spring near Holdanga. ' 513 



Tlie spring in question is situated in dense bush, on the dividing range 

 between the Wangape and Waihou rivers, the latter of -which runs into 

 Hokianga Harbour. The distance from tlie sea in a direct line is about 

 nine or ten miles, and is at a considerable elevation above sea level ; hence 

 the presence in large quantity of chloride of sodium is highly interesting, 

 showing, as it does, that there must be in the locality a deposit of salt, 

 probably some distance below the surface, which I should judge from the 

 fact of its not being more highly impregnated. As will be seen by the 

 analysis, this water contains about the same percentage of chloride of 

 sodium as ordinary sea water, but differs therefrom in the absence of sul- 

 phates. The following gives the chief constituents, so far as the small 

 quantity of the sample at my disposal would permit : — 



The solid matter equals 2937"558 gr 



Organic matter 

 Soluble silica 

 Carbonate of Magnesia 

 Chloride of Potassium 



,, Sodium 



Lime and Iron 

 Sulphuric Acid 

 Loss 



ains per gallon, composed of — 



51-115 



49-562 



18-710 



1-9 



27974 



traces 



18-871 



The sample was accompanied by a very large amount of fine sedimentary 

 deposit, which proved to be silicate of alumina, with a trace of iron and 

 lime. After standing some days the water was opalescent, acid reaction 

 and strong saline taste. From the appearance of the deposit, and a few 

 fragments of gravel brought separately, I should judge the locality from 

 whence the water was taken to be of a clay-slate formation ; but during the 

 coming summer I hope to make an examination of the place in which this 

 spring is situated, and a further one of the water. Spectroscopically I could 

 not detect lithia. As I have already mentioned, this spring ranks higher 

 than any other in this Colony, so far as records show, in regard to the 

 amount of alkaline chlorides present. 



While speaking with respect to springs not included in Mr. Skey's 

 report, I will add some information respecting two other mineral waters 

 from our district which have been analyzed. The first is located near 

 Whangarei, and is highly charged with carbonic acid gas. The springs 

 are surrounded with a vitreous-looking silica, and in places with large 

 quantities of a very light porous rock, presumed by the residents at first 

 to be meerschaum, but this I find on examination to be incorrect, the 

 chemical tests showing it to be a silicate of, alumina, and the microscope 

 resolving it into an infusorial earth, well worthy the consideration of our 



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