Natural Occurrence of Polythionic Acids

Abstract

IN 1937 I assisted Dr. A. L. Day in a survey of the thermal region of the North Island of New Zealand, and part of the work carried out for him was the collection of samples of the waters of the most vigorously boiling pools in the various hot spring areas. During the analyses at the Dominion Laboratory, Wellington, advantage was taken of the opportunity to examine the samples for the presence of polythionates. The method used was titration with sodium hydroxide solution after addition of mercuric chloride to the neutralized sample. The examination of seventeen acid waters from–seven areas showed the presence of polythionates in only two waters, but these were from the most active springs. One was the “Black Pool” at Ruahine, near Rotorua, the largest and most vigorously boiling pool in the thermal region, and the other, the “Black Geyser”, a perpetual spouter at Ketetahi Hot Springs on the slopes of Mt. Tongariro. On the authority of Mitchell and Ward, from whose book the method was taken¹, it was assumed that as the waters contained hydrogen sulphide, the only polythionate present was the trithionate. However, it has since been pointed out to me by Dr. A. Kurtenacker (private communication) that this is not correct.