194 
TUE GEOLOGIST. 
All the New Zealand hot-springs, like tiiose of leeland, abound in silica, and 
are to be divided into (wo distinct, classes, the one alkaline, and tin; other aeid. 
To the latter belong the soli'ataias, characterized by deposits of sulphur, and as 
never forming intermittent fountains. All the intermittent springs belong to 
the alkaline class, in which are also included the most of the ordinary boiling 
springs. Sul])hurets of sodium and potassium, and carbonates of j)otash and 
soda are the solvents of the silica, which, on the cooling and evaporation of the 
water, is deposited in such quantities as to form a strikmg characteristic in the 
ajjpearance of these springs. 
To cuter more deeply into the theory of these phenomena would be out of 
place here. It may be, however, well to mention that numerous facts prove 
that the action which gives rise to the hot-spriugs is slowly diminishing. 
Ere long these hot springs will ])robably be visited by many travellers, not 
only for the sake of their beauty and interest, but also for the mcdicmal virtues 
they ha' e been proved to possess. Already mauy Europeans have bathed in, 
and derived benefit from, the warm waters at Orakei-korako and llotomahana. 
There is an interesting legend current among the natives in reference to the 
origin of these hot springs. Tiie legend, as told by Te Heuheu, the great 
chief on the Taupo lake, is the following: — " The great chief Ngatiroirangi, 
after his arrival at Maketu at the time of tlie immigration of the Maories from 
Hawaiki, set oti" vnth his slave Ngauruhoe to visit the interior, and, iu order to 
obtain a better view of the country, he ascended the highest peak of the Toii- 
gariro. Here they suffered severely from cold, and the chief shouted to his 
sister on Whakari (Wiite Island) to send him some fire. This they did. 
They sent on the sacred fire they brought from Hawaika, by the taniwhas 
Pupu and Ta Hacata, through a subterranean passage to the top of Tougariro. 
The fire arrived just in time to save the life of the chief, but poor Ngauruhoe 
was dead when tlie chief turned to give him the fire. On this account the hole 
through which the fire made its appearance — the active crater of Tougariro — 
is called to this day by the name of the slave Ngauruhoe; and the sacred fire 
still burns within the whole underground passage along which it was carried 
from AVliakari to Tougariro." 
This legend affords a remarkable instance of the accurate observation of the 
natives, who have thus indicated the true line of the chief volcanic action in 
this island. 
Having described the older and more extensive volcanic phenomena of the in- 
terior. Dr. Hochstetter proceeded to notice the later phenomena of volcanic 
action in the immediate neiglii)ourhood of Auckland. 
The isthmus of Auckland is eom])letely perforated by volcanic action, and 
presents a large number of true volcanic hills, which, although extinct and of 
small size, are perfect models of volcanic mountains. These hills, once the 
funnels out of which toiTcnts of burning lava were vomited forth, and after- 
wards the strongholds of savage cannibals, are now the ornaments of a happy 
laud, the home of peaceful settlers, whose fruitful gardens and smiling fields 
derive their fertility from the siibstances long ago thrown up from the fiery 
bo\^•els of the earth. 
Dr. Hoehstetter's geological map of the Auckland district shows no less than 
sixty point s of volcanic cniption within a radius of ten miles ; the variety of 
which, together with the regularity of their formations, gives very great 
interest to tiiis neiglibourhood. The newer volcanic hills round Auckland are 
distinguished from the older ones iu the interior, not only by their age, but by 
the diirereut, eliaraeter of their lava, the older bein,^ tracliytic, while the Auck- 
land arc all basalt ic. The difference between trachyte and basalt consists in 
the minerals of which the rocks are composed. Trachyte is composed of a mix- 
ture of glassy felspar (sanidiu) and hornblende : obsidian and pumice-stone are 
