432 



Transactions. — Chemistry. 



From this analysis, etc., it ap^Dears the water itself is innocuous as a 

 beverage, but is heavily charged with a gas which is poisonous when 

 inhaled, and which," as it escapes, poisons the ah above, hence the effect of 

 this air on birds immersed in it. 



10. Mineral Waters of the Rotorua District. 



A very interesting series of waters has now to be described. They 

 were obtained from the famous geysers and hot water springs '^of Rotorua by 

 Captain Mair, at the suggestion of His Excellency the Marquis of Normanby, 

 and are reported on in the " New Zealand Gazette " of the 3rd May last. 



These waters are fifteen in number, and, as will be seen, while they are 

 generally characterized by the highly siliceous nature of their saline matter, 

 they divide as to their medicinal qualities into two classes. 



In the following account of the results obtained, I copy the temperature 

 of the several springs to which they refer, as also the physical description of 

 these springs, from the notes of Major Mair, which were attached to the 

 schedule forwarded with the water. 



The quantitative results are stated in grains per gallon. 



No. (1) — Is the water from Te Tarata, or the s^Dring which forms the 

 great white terrace of Eotomahana. This is a true geyser, having a large 

 crater-shaped basin 90 feet in diameter, the lip of which is about 70 feet 

 above the level of the lake. 



This basin is emptied by an explosive effort, which throws the water to 

 a height of 40 feet, emptying the basin, which again fills up rapidly. The 

 water trickles over the ledges of the terrace, depositing fresh layers of 

 sihceous sinter as it cools in its progress to the lake. The water in the 

 basin has a deep azure blue colour, and a temperature of 210° Fah. 



As received at the laboratory, it was faintly turbid, but without any 

 deposit, colourless, and havmg an alkaline reaction. 



Analysis. 



Silicate of soda 



. G8-48 



Mono-silicate of lime 



1-62 



,, magnesia 



•53 



, , iron 



•51 



Sulphate of potash 



— 



,, soda 



7-84 



Chloride of potassium 



2-87 



,, sodium 



, 62^61 



Phosphate of alumina . . 



traces 



Lithia 



• )) 





144-46 



All but soda are mono-silicates, the little excess of silica, 7"66, is included in the 

 soda-silicate. 



