CHEMISTRY. 205 



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the bisulphate readily fuses with the heat of a spirit-lamp, and 

 remains liquid to the end of the process, pure oxygen being 

 quietly evolved. 



Another oxygen process is reported in the " Chemical News." 

 On heating a concentrated solution of chloride of lime, with only 

 a trace of freshly prepared moist peroxide of cobalt, the hypo- 

 chlorite of lime is completely decomposed into chloride of calcium 

 and oxygen, and no chloric acid is formed. The evolution of oxy- 

 gen commences about 70 or 80, and continues in a regular 

 stream, with a slight frothing of the liquid. The peroxide made 

 use of in one experiment maj 7 be employed again, to decompose 

 a fresh quantity of hypochlorite of lime. 



PURIFICATION OF WATER. 



The London "Builder" says that Mr. Thomas Spencer, the 

 discoverer of electrotype, has made another important discovery. 

 He has ascertained that the magnetic oxide of iron, which.abounds 

 in rocky strata and in sands, etc., attracts oxygen, whether it ex- 

 ists in water or in air, and polarizes it; that this polarized oxygen 

 is the salubrity ing ozone ; that this ozone, so formed, destroys all 

 discoloring and polluting organic solutions in water, and converts 

 them into the sparkling and refreshing carbonic acid of the health- 

 ful spring. It is claimed that even sewerage water can be thus 

 almost instantaneously purified. 



Moreover, Mr. Spencer has discovered that the apparently me- 

 chanical process of filtration is itself magnetical, and it is now 

 known that all substances are constitutionally more or less subject 

 to magnetical influence ; thus all extraneous matter suspended in 

 water may be rapidly attracted in filtration, and so separated ; and 

 this may be done whether on a great scale or a small, either by 

 the magnetic oxide or black sand of iron, by a mixture of this with 

 ordinary sand, or by various other means ; and Mr. Spencer has 

 discovered a solid porous combination of carbon with magnetic 

 oxide, prepared from Cumberland haematite, which is said to have 

 very great filtering power. 



Mr. Booth, of Birmingham, England, has also recently promul- 

 gated a process for purifying water, for which meritorious claims 

 are also put forth, and which may be very properly introduced in 

 this connection. He placed in the water a neutral solution 

 of bisulphate of alumina, in the proportion of 1 ounce to 435 

 gallons. The sulphuric acid of the sulphate decomposes the 

 bicarbonate of lime in the water, and forms an insoluble sul- 

 phate of lime instead. The h}<drate of alumina being set freo, 

 forms with the organic matter in the water another insoluble com- 

 pound. Both these fall to the bottom, and the remaining freed 

 element, carbonic acid, lends, an agreeable quality to the water. 



WATER AS A GAS ABSORBER. 



Set a pitcher of water in a room, and in a few hours it will have 

 absorbed nearly all the respired and perspired gases in the room, 

 the air of which will have become purer, but the water utterly 



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