WATER. 



to Iiave given origin to many marvellous ftories, fuch as the 

 raining of blood, &c. (See the article Rain.) The fpe- 

 cific gravity of rain-vpater hardly differs from that of dif- 

 tilled water ; and from the minute portions of the foreign 

 ingredients which it generally contains, it is very fofl, and 

 admirably adapted for many culinary purpofes, and various 

 proct fTes ill different manufaAures and the arts. 



Srww-water equals, if not furpalfes, rain-water in purity, 

 when collefted under the fame circumftances, it being 

 for obvious reafons more free from animal and vegetable 

 impregnations ; thus Dr. Rutty found it perfectly fweet 

 after keepini;; it in a clofe vefTel for eighteen months. Snow- 

 water, like rain-water, even in its purefl ftate, yields traces 

 of muriatic acid, and perhaps alfo of the nitric. 



Hail-ivater may be compared to fnow-water, which it 

 clofely refembles : indeed 



Ice-tvater in general is very uure, as the air and faline fub- 

 ftances are feparated by freezing. Common ice-water, how- 

 ever, is lefs pure than rain and fnow water, as the foreign 

 fubllances, though perhaps feparated by freezing, ftill re- 

 main incorporated with the ice, fo that it is impoflible to 

 melt the ice without retaining at leaft a portion of thefe fo- 

 reign matters. 



Dew, being depofited chiefly from the lower parts of the 

 atmofphere, is commonly much more impure than rain or 

 fnow water. According to Dr. Rutty's obfervatioiis, it 

 foon becomes foetid and ofFenfive. It yields alfo more feiifi- 

 ble traces of the prefence of muriatic acid than rain-water. 

 This fluid, however, collefted at different places and 

 times, differs exceedingly in its properties, as might be na- 

 turally expefted. 



c. Spring-water includes tuell-wzter, and all others that 

 arife from fome depth below the furface of the earth, and 

 which are ufed at the fountain-head, or at leaft before they 

 have run any confiderable diftance expofed to the air. Al- 

 though all fpring-waters are originally of atniofpheric origin, 

 yet they differ from one another according to the narure of 

 the foil or rock from which they ifTue ; for though the in- 

 gredients ufually exifting in them are in fuch minute quanti- 

 ties as to impart to them no ftriking medicinal or fenfible pro- 

 perties, and do not render them unfit for common purpofes, 

 yet they modify their nature very confiderably. Hence the 

 water of fome fprings is laid to be hurri, others /ft, fome 

 Jwset, others brackifh, &c. according to the degree and nature 

 of the imprf'guatiiig ingredients. Common fprings pafs infen- 

 libly into mineral or medicinal fprings, as their foreign con- 

 tents become larger or more unnfual ; or in fome inftances 

 they derive medicinal celebrity from the abfenceof thofe in- 

 gredients ufually occurring in fpring-water ; as, for example, 

 is the cafe with tlie Malvern and other fprings. Almoil all 

 fpring-waters poflefs the property termed hardnefs in a greater 

 or lefs degree. This hardm-is, as we formerly mentioned, 

 depends ch'efly upon the fiilphate and carbonate of lime 

 which they hold in folution. The quantity of thefe earthy 

 falls varies very confiderably in different inftances ; but Dr. 

 Saunders obfervrs, that when they exilf in the proportion of 

 five grains in the pint, fuch water will be hard, and from 

 its properly of decompofing foap will be unfit forwafhing, 

 and many other purpofes of lioufehold ufe or nianu failures. 

 The wa:er of deep wells, according to Dr. S., is always, 

 ttteris paribui, much harder than that of fprings which over- 

 flow tlieir c'lannel ; but there are many exceptions to this rule. 

 The fojiiitfs of fpring-waters depends on their containing 

 fmaller proportions of the earthy falts above-mentioned. 

 Spring-waters arc faid to be brackifh, when they contain a 

 fmall proportion of the muriates of foda, magnefia, or lime, 

 as is frequently the cafe in the neighbourhood of the fca. 



Sweetnifs is generally underftood as oppofed to bmcki/hnefi or 

 fator when applied to fpring-waters. The fpecific gravity 

 of fpring-waters in general is greater than that of diailled 

 or any other potable water. See Spring. 



d. Running waters include riiier-waters, and every other 

 fpecies of water expofed to the air, and moving in an open 

 channel. On this part of our fubjeft we cannot do better 

 than quote from Dr. Saunders. " River-water," fays Dr. 

 S., " in general is much fofter, and more free from earthy 

 falts than fpring-waters, but contains lefs air of any kind ; 

 for by the agitation of a long current, and, in moft cafes, a 

 great increafe of temperature, it lofes common air and car- 

 bonic acid, and with this lafl much of the lime which it 

 held in folution. The fpecific gravity thereby becomes lefs, 

 the tafte not fo harfh, but lefs frefh and agreeable, and out 

 of a hard fpring is often made a ftream of fufficient pu- 

 rity for moft of the purpofes where a foft water is required. 

 Some ftreams, however, that arife from a clean filecious 

 rock, and flow in a fandy or ftony bed, are from the outfet 

 remarkably pure, fuch as the mountain lakes and rivulets 

 in the rocky diftricis of Wales, the fource of the beautiful 

 waters of the Dee, and numberlefs other rivers that flow 

 through the hollow of every valley. Switzerland has long 

 been celebrated for the purity and excellence of its waters, 

 which pour in copious ftreams from the mountains, and give 

 rife to fome of the fin-ft rivers in Europe." — " Some rivers, 

 however, that do not take their rife from a rock-, foil, and 

 are indeed at firfl confiderably charged with foreign mat- 

 ter, during a long courfe, even over a richly cuhivated plain, 

 become remarkably pure as to faline contents, but often 

 fouled with mud and vegetable or animal exuvise, wiiich are 

 rather fufpended than held in true folution. Such is that of 

 the Thames, which, taken up at London at low water, is 

 very loft and good water, and after refl and filtration it 

 holds but a very fmall portion of any thing that could prove 

 noxious, or impede any manufafture. It is alfo excellently 

 fitted for fea-flore, but it here undergoes a remarkable fpon- 

 taneous change. No water carried to fea becomes putrid 

 fooner than that of the Thames. When a cailc is opened, 

 after being kept a month or two, a quantity of inflammable 

 air (carbuietted or fulphuretted hydrogen) efcapes, and the 

 water is fo black and ofFenfive as fcarcely to be borne. 

 Upon racking it off, however, into large earthen veffels, 

 and expofing it to the air, it gradually depofits a quantity of 

 black flimy mud, becomes clear as cryftal, and remarkably 

 fweet and palatable. The Seme has a high reputation in 

 France, and appears, from the experiments of M. Parmentier, 

 to be a river of great purity. It might be expefted that a 

 river which has paffed by a large town, and received all its 

 impurities, and been ufed by numerous dyers, tanners, hat- 

 ters, and the like, that crowd to its banks for the conve- 

 nience of plenty of water, fhould acquire thereby fuch a 

 foulnefs as to be very perceptible to chemical examination 

 for a confiderable ditlance below the town ; but it appears 

 from the moft accurate examination, that where the ftream 

 >is at all confiderable, thefe kinds of impurity have but little 

 influence in permanently altering the quality of the water, 

 efpecially as they are for the moil part only fufpended, and 

 not truly dilTolved ; and therefore mere refl, and efpecially 

 filtration, will reftore the water to its original purity. Pro- 

 bably, therefore, the moft accurate chemift would find it 

 difficult to diftinguifh water taken up at London from that 

 procured at Hampton-court, after each had been purified by 

 fimple filtration." The water of the Ebro alfo, notwith- 

 ilanditig this river paffes through feveral large towns, is re- 

 markable for its purity. In general, thofe rivers which iiTue 

 from lakes are moil pure and tranfparent, while thofe chiefly 



fupplied 



