1100 WATER, PURIFICATION OF 



The analysis made by Dr. Muspratt of the Buxton water is as follows : 



Carbonate of lime, CaOCO 2 8-541 



Carbonate of magnesia, MgOCO- . ...... 3'741 



Carbonate of iron, FeOCO 2 0-082 



Chloride of calcium, CaCl 

 Chloride of magnesium, MgCl 

 Chloride of sodium, NaCl 

 Chloride of potassium, KC1 

 Sulphate of lime, CaOSO* . 

 Silicic acid, SiO z 

 Organic matter 



. . 1-227 



. . 0-463 



. . 2-404 



. 0-260 



. 0-330 



. . 1-044 



. . 0-341 

 Phosphate of lime and alumina, fluoride of calcium, nitric 



acid, &c. 1-076 



19-510 



The celebrated Geysers of Iceland are the hottest known springs in the world. 

 From experiments made by Prof. Bunsen, we learj tnat at the depth of only 74 feet, 

 at the bottom of the tube a column of water may be in a state of rest, and yet possess 

 a heat of 120 Cent, or 248 Fahr. What then will be the temperature of such water 

 at the depth of a few thousand feet ? The Geyser water contains in 10,000 parts : 



Forchhammer. Pfaff. 



Silicic acid 4-09 8'00 



Soda 1-32 



Chloride of sodium 1-68 1-68 



Sulphate of soda (and magnesia) . . . .0-62 1-32 



Sulphate of lime 0-34 



7-96 11-00 



By cooling alone about one-tenth of the silicic acid separates ; for the water 

 which Forchhammer received in sealed flasks became cloudy, and left that quantity 

 of silica. 



WATER-PRESSURE MACHINERY FOB MINES. See HYDRAULIC 

 MACHINEET. 



WATER-PROOF CIiOTK. See CAOUTCHOUC. 



"WATER, PURIFICATION OF. This subject has been already dealt with to 

 some extent while on the subject of filters, and when speaking of the influence of 

 animal-charcoal. Spencer, the discoverer of the electrotype process, appears to have 

 made a discovery proving that magnetic oxide of iron and the protocarbide possess the 

 property of purifying water. 



After trying a number of experiments with various descriptions of rocks and 

 minerals, Mr. Spencer found that those containing protoxide of iron (even where it 

 was chemically combined with other substances) effected the filtration of water from 

 even suspended impurity better than any others. Acting on the idea thus suggested, 

 he found that the same oxide, when isolated in the state of ' magnetic oxide,' not only 

 freed water from turbidity more effectually than an equal thickness of sand, but 

 effected its decolouration with marvellous rapidity. On the other hand, the earthy 

 substances entering into the composition of the same rocks, such as silica and alumina, 

 when isolated, were, in the latter respect, perfectly inert. From this it was evident 

 that the protoxide of iron, as magnetic oxide a substance which enters into the com- 

 position of so many rocks was one of nature's chief agents of purification. A most 

 striking experiment was made with some bog-water, darker in colour than ordinary 

 porter, which had been procured from the soakings of an Aberdeenshire peat-bed. 

 When brought into contact with the magnetic oxide, it was deprived of its colour almost 

 instantaneously, and carbonic acid substituted in its place. 



Perhaps the most extraordinary circumstance is that the magnetic filtering medium 

 itself suffers no deterioration after any period of operation. Of course, if its surface be- 

 comes fouled with slimy impurity, it requires washing. Its province is confined to 

 forcing the oxygen, always present in the water, into combination with the impure 

 organic matter, and thus converting it into carbonic acid, which gas conferred freshness 

 and salubrity on all waters in which it was found. In these results the occult action of 

 catalysis was, for the first time in the history of science, brought at will into artificial 

 every-day operation. 



The magnetic oxide was not to bo understood as ordinary oxide (rust) of iron. It 

 was, on the contrary, a black crystalline body, hard but brittle, and analogous, in 

 perhaps all respects, to the body formerly termed ' loadstone.' Below redness it 



