CHEMISTRY. 



151 



sidered that in this process ozone and antozone 

 are simultaneously liberated, and that these 

 uniting form common oxygen. Although M. 

 Kuhlmann, among others, has done much to 

 develop the uses and value of the baryta-com- 

 pounds in the arts, yet the peroxide, at least, 

 has not hitherto been produced and sold as a 

 commercial article; so that it would as yet 

 have to be specially prepared. The author of 

 the paper, however, speaks of arrangements 

 having been made for furnishing this compound 

 more cheaply, and he states that the price of it 

 has already been reduced from that formerly 

 holding, viz., 5s. per Ib. Other peroxides could 

 be used, but such have proved less easy of prep- 

 aration than that of barium. Chem. News, 

 March 12, 1864. 



M. Fleitmann has a new process, depending 

 on the circumstance that, when a concentrated 

 solution of hypochlorite of lime (bleaching 

 powder) is warmed with a little oxide of cobalt, 

 the former is completely decomposed into chlo- 

 ride of calcium, which remains in solution, and 

 oxygen, which escapes. The evolution of the 

 gas takes place at from 70 to 80 0., and is 

 steady and regular ; and the whole of the quan- 

 tity contained in the hypochlorite is given off. 

 From to y^th of one per cent, of the cobalt 

 oxide [one account states, the hydrated sesqui- 

 oxide] suffices; and this serves to decompose 

 an indefinite amount of the bleaching salt, 

 since, if the oxide be separated and kept moist 

 it may be used over again as often as desired. 

 The author's theory of the process is that a 

 lower oxide continually takes oxygen from the 

 hypochlorite, passing into a higher, and return- 

 ing at once again into the state of the lower 

 oxide and free oxygen. The cobalt oxide need 

 not be prepared separately ; a few drops of any 

 soluble cobalt salt added to the liquid sufficing 

 to form it. The solution of hypochlorite must 

 be cleai-, as it can be obtained by decantation, 

 and flasks may be filled with it to fths of their 

 capacity ; while, on the large scale, steam-boil- 

 ers could be used: The materials employed are 

 quite bulky, and the volume of gas secured is 

 proportionally much less than in case of chlorate 

 of potash ; but while in cost of a given volume 

 of gas furnished these two methods are much 

 the" same, the new one has the advantage in 

 steadiness and manageableness, as for lecture 

 experiments in which the use of the gas-holder 

 is not convenient. Original paper in Ann. der 

 Chem. und Pharm., cxxxiv. 64. 



Mr. R. W. Artlett, having experimented 

 largely with the process just named, finds that 

 moist peroxide of iron or oxide of copper serves 

 the like purpose with that of cobalt. A few 

 drops of the nitrate of copper will suffice for 

 the reaction. It is stated that M. Archereau, 

 of Paris, obtains oxygen by raising to intense 

 heat in a furnace somewhat like that of Siemens 

 a mixture of silica and sulphate of lime (burned), 

 silicate of lime being formed and oxygen with 

 sulphurous acid escaping, the latter of which 

 he proposes to remove by subjecting the mix- 



ture to pressure, and absorbing any remnant 

 with milk of lime. The process is said to fur- 

 nish the gas so cheaply that it may be economi- 

 cally used with coal gas to make a lime light, 

 in place of the ordinary arrangement of burners, 

 for stores or halls. Still another process is that 

 of M. Carlevaris, which consists in heating to- 

 gether the black oxide of manganese and silica 

 (MnO 3 and S5O 3 ), when a silicate of the pro- 

 toxide of manganese is formed, and one equiva- 

 lent of oxygen set free. 



Iodine. M. Schwartz has indicated two 

 methods of extracting iodine from the saline 

 matter of certain mother-liquors : the first, thnt 

 of dissolving the salts in water, and treating 

 with bichromate of potassa and sulphuric acid, 

 when the iodine is at once deposited ; the sec- 

 ond, that of boiling the salts with perchloride 

 of iron, and dissolving the displaced iodine by 

 bisulphide of carbon. The last-named method 

 may perhaps serve for the separation of iodine 

 from bromine. 



Nitrogen, &c. In one of a series of papers 

 entitled " Contributions to Chemistry from the 

 Laboratory of the Lawrence Scientific School," 

 and which appear in the American Journal of 

 Science, Prof. W. Gibbs presents (May, 1864) a 

 mode of determination of nitrogen by weight, 

 as also methods of separation of cerium from 

 several other metals, and the uses of hypo- 

 sulphate of soda and fluohydrate of fluoride of 

 potassium in certain analyses of metals. The 

 subject of separation of metals is continued in the 

 number of the same journal for January, 1865. 



Electro- Chemical Separation of Metalloids. 

 The electro-chemical method of separation of 

 bodies from their combinations is already found, 

 in case of simple bodies generally, and of a large 

 number of their principal compounds, to serve, 

 under most circumstances, better than the modes 

 offered by pure chemistry. Among metalloids, 

 the preparation of which by this method is of 

 most interest, -are, nitrogen, obtainable from 

 ammonia or nitric acid ; as also ch lorine, bro- 

 mine, and iodine. These are all procured by 

 essentially the same method ; that, namely, of 

 decomposing in a U-shaped tube the hydrogen- 

 ated combination of the given metalloid, using 

 graphite conductors as the electrodes. Arsenic 

 is of all the metalloids the most easily isolated, 

 and that altogether, and from a variety of ar- 

 seniferous substances. Boron and silici-um are 

 not easily separated in any considerable quan- 

 tities. 



A very Sensitive Reaction for Iron. Natan- 

 son has observed that sulpho-cyanide of iron is 

 soluble in ether, and that when a solution con- 

 taining a trace of peroxide of iron and sulpho- 

 cyanide of potassium, but exhibiting no visible 

 red tint, is agitated with ether, the latter assumes 

 a rose color resembling that produced in chlo- 

 roform by traces of iodine. Of course, the pre- 

 cautions usual in testing for iron by sulpho- 

 cyanide of potassium, must be taken in employ- 

 ing Natanson's process. Note in Amer. Jour, 

 of Science, September, 1864. 



