80 Intelligence and Miscellaneous Articles. 



In the meantime he inquires how these com'^ounds, which are 

 found at the positive jiole, are formed. They did not exist in the 

 solution. It can h.ardly be sujiposed that a jiortion of the metal is 

 carried to the positive ]5ole and then o.xidized by absorbing the 

 oxygen disengaged at that pole. It is more probable that the 

 division takes place at the negative ])ole ; that a portion of the 

 oxide gives up its oxygen to another portion, which, thus acquiring 

 acid properties, passes to tiie positive pole. If this be exactly the case, 

 in the decomposition of the lead salts, one half of the lead would be 

 deposited at the positive pole in the form of binoxide of lead, or 

 plumbic acid, and the other lialf at the negative pole in the metallic 

 state. In this way the law of chemical decompositions would not 

 be altered by the division in question. 



As regards the dei)endcnce of this pheenomenon upon the intensity 

 of the current, a solution of nitrate or acetate of lead submitted to 

 the action of 1, 2, 3, 20, or 100 Bunsen's elements disposed in a ten- 

 sion series, gives the black substance at the positive pole almost in- 

 stantaneously, and on the negative pole, lead iu narrow, brilliant, 

 crystalline laminae, with this sole difference, that the black product 

 of 20 or 100 elements is not smooth at the surface like that of two 

 elements ; it is dull, not compact, &c. With a single element the 

 experiment has a peculiar character, — no gas is evolved from either 

 pole. This is in favour of the opinion that a portion of the oxide 

 yields its oxygen to the undecomposed portion, which becomes sur- 

 charged with oxygen, without the decomposition of water. 



Nitrate of bismuth also gives a reddish -brown colour to the 

 positive plate.— Co»z;;;es Rendus, Oct. 5, 1S57, p. 449. 



ON THE COERCIVE POWER OF PURE IRON. 

 BY A. MATTIIIESSEN, PH.D. 

 Having jirepared some galvanoplastic iron both out of a solution 

 of pure protochloride and protosulphate of iron, in order to ascertain 

 whether galvanoplastic metals, precipitated from different solutions 

 and under different circumstances from the same solution, take the 

 same place in the thermo-electric series, or in other words, give no 

 thermo-electric currents with each other (which, however, they 

 appear to do), I found that iron thus preci])itated possesses great 

 coercive powers, and retains its magnetism undiminished for a length 

 of time. It is very brittle, and its hardness is equal to that of tem- 

 pered steel. 



ON THE rORMATION OF ISATINE BY OZONE. ■' 

 BY PROF. O. L. ERUMANN. 



The author has found that pure indigo-blue, made into a paste 

 witii water, is readily converted into isatinc by ozonized air. — Journ, 

 fur Praht. Cliemic, Ixx. p. 209. 



