Came of the peculiar Condition of Iron. 259 



gen which is either in a combined state or set free by electro- 

 jylic action, and by no means to oxygen which is in its usual 

 condition. If iron be voltaically associated with platina and 

 put into water containing oxygen dissolved, the former metal 

 is oxidized whether the platina be plunged into the fluid 

 before or after the iron. If zinc be the substance put into 

 voltaic association with iron, the latter is not in the least af- 

 fected by the oxygen, which the water holds dissolved. For 

 these last four months I have kept a combination of both 

 metals within common water, which has been continually ex- 

 posed to the air, and the surface of the iron is at this present 

 moment as brilliant as it was when I put that metal into the 

 water ; whilst the zinc appears surrounded by a thick cloud 

 of its oxide. In the two cases stated the electro-chemical 

 laws hold good, whereas they do not at all agree with the 

 phaenomena which are referable to the peculiar condition of 

 iron. I must openly confess that the different way in which 

 the same current makes the iron act upon the oxygen appears 

 to me as rather unfavourable to my hypothesis of a chemical 

 polarity of the iron particles ; but on the other hand it must 

 be allowed, that the fact alluded to is likewise very much at 

 variance with the principles of the electro-chemical system 

 of the present day. 



There is another objection to which my hypothesis will, per- 

 haps, be thought liable. It may be said that the solid state 

 of iron does not allow its particles the motion required for 

 obtaining the peculiar arrangement of their poles mentioned. 

 It is a point generally adopted by philosophers, that the 

 atoms of no body do immediately touch each other, and it is 

 supposed that the distance at which any two contiguous par- 

 ticles are placed from each other surpasses by far the diame- 

 ter of each atom. If such be the case, I cannot conceive 

 why the molecules of iron should not be capable of being 

 turned by some force, being superior to that by which they 

 are kept together under ordinary circumstances. There are, 

 indeed, some facts which put it beyond doubt that the molecu- 

 lar constitution of a solid body may be essentially modified 

 without having recourse to its liquefaction or vaporization. 

 Gustave Rose, in a very interesting paper lately published in 

 PoggendoriF's Annalen*, has demonstrated, that arragonite 

 can easily be transformed into calcareous spar by moderately 

 heating the former substance. Such a change cannot take 

 place without an internal motion of the particles of carbonate 

 of lime, the form of crystallization as well as the specific gra- 

 vity of the compound becoming considerably modified under 



• And of which a translation appeared in Lond. and Edinb. Phil, Mag., 

 vol. xii, p. 465.— Ecu. 



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