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Missouri Botanical 
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526 THE SCIENTIFIC MONTHLY. 
following facts : first, there is no notice of this fountain in the early history of the 
colonization of the island 986 years ago, at which time the tube would have been 
only three feet deep, and its eruptions too slight to attract attention; second, 436 
years afterwards, when the tube would have been twenty-six feet deep, and the 
eruptions proportionally important, this geyser is mentioned; third, accurate 
records of all occurences were kept by the early inhabitants, and if so remarkable 
a phenomenon had existed at the time, it would not have been left unnoticed/’— 
Richardson. 
This silicious deposit often assumes the most beautiful and variegated colors 
and tints. In the Yellowstone this is peculiarly marked; at one basin will be 
seen through the transparent waters, an exquisite rose-colored lining, at another 
bright red, one is a light green another golden and so on through many varieties. 
A most delicate tint of red is produced by a deposit of oxide of iron; sulpher 
causes exquisite shades of yellow. Still others are stained with shades of green, 
all these colors are brilliant as the brightest aniline dyes.” 
Another singular feature is that though many hot springs contain enough 
foreign ingredients to be designated mineral, still in this region much of the water 
is clear, sparkling and free from taste, seeming to be remarkably free from harmful 
impurities and is most excellent for drinking and cooking purposes. 
In the vicinity of all hot waters, holding silica in solution, a curious phenom¬ 
enon occurs in the growth of the vegetation. Mosses, grass and trees undergo the 
process of petrifaction, and become converted substantially into a species of stone, 
still retaining, however, the form, appearance and structure which was characteristic 
of them when living vegetables. The silicious solution is absorbed by the circu¬ 
lating fluid of the plant and becomes deposited within its substance, effectually 
preventing the process of decay, and substituting the stony for the woody material. 
In the territory of New Mexico large forests of this silicified wood of great 
perfection and beauty are still seen; tall trees still erect as in the vigor of their 
growth, stand as monuments of the time when that particular region was over¬ 
flowed by the silicious waters. Certain parts of the region of the Yellowstone and 
other places in our Western territories, afford the same phenomenon, as also do, 
though on a smaller scale, the plants in the immidiate vicinity of the hot springs 
of Iceland and the Azores. 
But geyser springs do not always emit water in its extreme fluid state, for in 
these western regions of comparatively recent formation, geologically speaking, 
there exist localities where the surface of the ground consists of a hardened crust 
of but a few inches in thickness, underneath which lies a vast quantity of soft 
tenacious mud. This substance heated to an extreme degree, presents conditions 
under which we would expect eruptions to occur. Such is indeed the case, and 
the phenomenon of mud geysers ” presents itself to oiir view. 
“The contents of most of them were of the consistency of thick paint, which 
they greatly resemble, some being yellow, some pink, others red and some dark 
brown. This semi-fluid was boiling at a fearful rate, much after the fashion of a 
hasty-pudding in the last stages of completion. The bubbles, often two feet in 
