A manual of practical hygiene for students, physicians, and health officers . etimes with apparently inexhaustible reservoirs which haveheld the water in storage for ages. Sometimes thev derive their water 390 WATER from fissures draining away the water of surface rivers and lakes, as isproved by the occiisional occurrence in the overflow of small fish witheyes. Artesian wells have been known in China and Egyjit from veryancient times, and centuries ago they were introduced into the prov-ince of Artois (Artesium), from which their name is derived. Theyare exceedingly numerous in the western an
A manual of practical hygiene for students, physicians, and health officers . etimes with apparently inexhaustible reservoirs which haveheld the water in storage for ages. Sometimes thev derive their water 390 WATER from fissures draining away the water of surface rivers and lakes, as isproved by the occiisional occurrence in the overflow of small fish witheyes. Artesian wells have been known in China and Egyjit from veryancient times, and centuries ago they were introduced into the prov-ince of Artois (Artesium), from which their name is derived. Theyare exceedingly numerous in the western and southwestern parts of theUnited States, Avhere they have produced enormous results in convert-ing arid, waste lands into fertile farms. Some of them are exceedinglydeep, and pass through stratum after stratum of ditferent formationsbefore water is reached. Since the temperature of the earth increases 1 degree Fahrenheit forabout 55 feet of depth, it follows that water from these very deep wells Fig. 31. Ordinary Aries .Perifrjii,^ Sfrrt \ t 1 f>l .Srr/-,, >-r,tirjn. ;„ A/ //. ,. Vd/j. Ma/,///„,///kGeological formation favorable to the obtaining of water by means of artesian wells. is materially warmer than that from the upper subsoil. Distinctly hotwater from deep sources is rarely fit for ordinary domestic purposes,because of the large amount of mineral matters present in solution byreason of the greater solvent power of water when hot than when they acquire an abundance of salts, which, taken into the body,influence its functions and act as medicines. The presence of organicmatters is of importance on account of their reducing power. Thesulphuretted hydrogen so common to mineral springs is due to theaction of these matters on sulphates. Irrespective of the changes wrought by increased temperature,the water yielded by this class of wells varies very widely in charac^ter. It may bear no resemblance whatever to the other waters ofthe same district, nor is t
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishe, booksubjecthygiene
