Page 20 - 1915, Springs of CA.

20 SPEINGS OF CALIFOBNIA.

bonate) and other carbonate rocks by the action of acids. The de-
composition of organic matter also gives ris° to carbon dioxide.
Hydrogen sulphide (the gas which gives the "rotten-egg" odor to
sulphur waters) is believed to be sometimes derived by the action of
organic matter on calcium sulphate, in the presence of carbon dioxide,
and this seems to be a plausible source for it in many saline meadow
and marsh waters. In hot alkaline waters it may be produced by
the action of steam on metallic sulphides. When present in notable
amount it is apt to cause corrosion, rotting, and discoloration of
articles and fabrics left within its reach.
Organic matter is present in small amount in many waters and is
probably derived from vegetable material in the surficial layers of
soil. Several hypothetical compounds so derived, including crenic
and apocrenic acids, have been calculated by chemists, but it is not
certain that they actually exist. Beregin is a transparent, gelatinous,
mucus-like substance, the product of certain algae that grow in ther-
mal sulphur springs and impart the odor and flavor of flesh broth to
the water. These algse are probably the peculiar feature of so-called
chicken-soup springs.
Vegetable growths that are characteristic of certain classes of
waters are found in many mineral springs. Perhaps the most
noticeable of these are the varieties of algse that live in warm and
hot springs and especially in sulphur springs. The color and texture
of the growths vary with the temperature of the water and the
rapidity of the current, as well as with the variety of the organism
itself. The following observations by Weed on the algse in Yellow-
stone National Park illustrate this change.1
The general sequence of colors is well illustrated by the occurrence of such growths
in overflow streams with a constant volume, such as the outlet of the Black Sand [a
spring in Yellowstone Park]. As the water from this spring flows along its channel
it is rapidly chilled by contact with the air and by evaporation, and is soon cool
enough to permit the growth of the more rudimentary forms which live at the highest
temperature. These appear first in skeins of delicate white filaments which gradually
change to pale flesh-pink farther downstream. As the water becomes cooler this
pink becomes deeper, and a bright orange, and closely adherent fuzzy growth, rarely
filamentous, appears at the border of the stream, and finally replaces the first-mentioned
forms. This merges into yellowish-green which shades into a rich emerald farther
down, this being the common color of fresh-water algse. In the quiet waters of the
pools fed by this stream the algse present a different development, forming leathery
sheets of tough gelatinous material with coralloid and vase-shaped forms rising to
the surface, and often filling up a large part of the pool. Sheets of brown or green,
kelpy or leathery, also line the basins of warm springs whose temperature does not
exceed 140° F., but in springs having a higher temperature the only vegetation present
forms a velvety, golden-yellow fuzz upon the bottom and sides of the bowl. This
growth is rarely noticed in springs where the water exceeds 160° except at the edge
1 Weed, W. H., Formation of travertine and siliceous sinter by the vegetation of hot springs: U. S. Geol.
Survey Ninth Ann. Kept., pp. 657-658,1899.