74 PHYSICAL GEOGRAPITY OF THE SEA. 
The temperature of springs varies from icy coldness to boiling 
heat. Cold. springs arise when the waters, by which they are 
fed, descend from high mountains or do not penetrate a great 
way into the bowels of the earth; but if the filtering waters 
reach a depth which is constantly of a higher temperature, they 
then gush forth in the form of warm or even boiling springs. 
A crowd of agreeable associations attaches itself to the idea 
of sources and springs, for they are generally both pleasing and 
useful to man. How we long in summer for the refreshing 
waters of the cool fountain issuing from the mountain side, and 
murmuring through the woods. The lover of nature spends 
hours near some solitary spring, and forgets the flow of time, as 
he observes the bubbling and listens to the sweet music of its 
crystal waters. A luxuriant vegetation marks their progress, 
though all around be burnt up by the scorching sun. Along 
their margin many a wild flower blooms, and herbs and shrubs 
and trees rejoice in a more vivid green, and statelier growth. 
There also congregate such members of the finny race, as 
delight in cooler streams of untainted purity, and birds love to 
build their nests among the sheltering foliage. Thus a little 
world forms around the gushing spring, and shows on a dimi- 
nutive scale, how all that lives and breathes depends upon the 
liquid element for its existence. 
While the waters filter through the earth they naturally 
dissolve a variety of substances, and all springs are more or 
less mixed with extraneous particles. But many of them, par- 
ticularly such as are of a higher temperature and consequently 
arise from deeper strata, contain either a larger quantity or 
so peculiar a combination of mineral substances as to acquire 
medicinal virtues of the highest order, and to become objects 
of importance to a large portion of mankind. Numberless 
invalids annually flock to the hygeian fountains which nature 
unceasingly pours forth from her mysterious laboratory, and 
are by them restored to the enjoyments of a pleasurable ex- 
istence. 
How truly wonderful is the chain of processes which first 
raises vapours from the deep, and eventually causes them to 
gush forth from the entrails of the earth, laden with blessings 
and enriched with treasures more inestimable than those the 
miner toils for! 
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