264 Dr. Webster on St. Michaei 
tinct loud explosions occur at short intervals, which are 
succeeded by a very perceptible elevation of the body of 
water within the basin. This is attended with a loud hiss- 
ing noise and the escape of great quantities of sulphuretted 
hydrogen gas, steam and sulphurous acid vapour.” The 
water of these springs is used in bathing houses erected near 
them and found highly beneficial in many complaints. 
** Wherever the water has flowed, depositions of siliceous 
sinter have accumulated, and circular basins, composed 
entirely of this substance, have been here and there formed 
round a spring. The siliceous matter rises, in many places, 
eight or ten inches above the level of the water, and is of- 
ten exceedingly beautiful. Vegetables, grass, leaves and 
imilar substances which have been exposed to the influ- 
ence of the water are more or less incrusted with silex, and 
exhibit all the progressive steps of petrifaction ; some being 
soft, and but little differing from their natural state ; while 
others are partly converted into stone, or perfectly cousoli- 
dated.” All these masses are more or less abundant in sul- 
phur, often crystallized and constituting splendid specimens. 
Much of the sinter bles that of the gey f lceland— 
much is represented as being far more beautiful. One va- 
riety which has been described in a former number of this 
vol. Journal, pa. 26 is distinguished. by its structure and 
chemical composition (containing 16.35 per cent of water) 
and Dr.W. proposes to designate it by the name ‘* Michael- 
ite.” Silex occurs in the cavities of the massive sinter in 
stalactites, some of which are covered with “ small, brilliant 
erystals of quartz.” i ue dyed 
Near the springs is a remarkable breccia formed of frag- 
ments of lava, pumice, sinter and obsidian, cemented by 
siliceous matter. From observing the ferruginous deposi- 
tion of some springs of cold water within a few inches of 
the hot springs, and from the occurrence of pebbles having 
a metallic stain, Dr. Webster suspected the existence of 
sulphuretted iron and caused an extensive examination to 
be made. Ata considerable depth below the surface, his 
~_ itd 
up. Most of the pieces were as large as aman’s head, wi 
regular globular form.” These pieces had all the char- 
acters of iron pyrites and in the author’s view, the existence 
¥ 
