CHEMISTRY. 393 



temptiug to obtain evidence of definite compounds of metals in alloys 

 by dissolving the alloys in a liquid capable of acting on both metals and 

 determining tbe electromotive force between the alloy and a less pos- 

 itive metal, tbe author made the following remarks : " With reference to 

 the action of metals on acids generally it is probably impossible for the 

 chemist to pronounce definitely in favor either of the modern view that 

 the metal directly displaces the hydrogen of the acid, or of the older 

 view that the metal displaces the hydrogen from water, the resulting 

 oxide and the acid then interacting to form a salt; the decision of this 

 question must apparently depend upon the determination of the nature 

 of the phenomena during electrolysis of an acid solution. If the acid 

 alone be the electrolyte, then doubtless the modern view is the correct 

 one; but if both water and acid are electrolyzed, and in proportions 

 which vary according to the conditions, then both the old and new views 

 of the nature of the action between a metal and the solution of an acid 

 are correct, and the two kinds of change may go on side by side." 

 (Chem. News, liii, 212.) 



Chemical Behainor of Iron in the Magnetic Field, by Edward L Nich- 

 ols. — When finely-divided iron is placed in a magnetic field of consid- 

 erable intensity and exposed to the action of an acid, the chemical 

 reaction differs in several respects from that which occurs under ordi 

 nary circumstances. The cause of one such difference may be found in 

 the fact that the solution of iron in the magnetic field is in a sense 

 equivalent to its withdrawal by mechanical means to an infinite distance. 

 Mechanical removal requires the expenditure of work, and the same 

 thing is doubtless true of what might be called its chemical removal. 

 In other words the number of units of heat produced by the chemical 

 reaction should ditfer, within and without the field, by an amount equiv- 

 alent to the work necessary to withdraw the iron to a position of zero 

 potential. 



Experiments with aqua-regia and iron show that the speed of reaction 

 is greater in the magnetic field than without and that the heat of chem- 

 ical union is much greater. Under the influence of the magnet, aqua- 

 regia and iron produce nitrous fumes, whereas when the influence of 

 the magnet is removed only hydrogen is generated. 



When experimenting with iron and nitric acid, interesting effects of 

 magnetism on the passivity of the iron were observed; five grams of 

 powdered iron lay in a beaker close above the ])oles of the electro-mag- 

 net which was in circuit. Some cold nitric acid was poured upon t)'e 

 iron, but the latter remained passive. Wishing to note the character of 

 the reaction the author warmed the beaker slightly, then pla(;ed it upon 

 the poles of the magnet and put a thermometer into the solution to get 

 its temperature. The bulb of the thermometer touched the iron in 

 stirring the acid, when the hitherto passive mixture burst almost ex- 

 plosively into effervescence, and red nitrous fumes were liberated. 

 Removal of the solution from the field of the magnet restored the pas- 



