36 



SCIENCE. 



[Vol. I., No. 2. 



the autograph of St. Luke. The details of 

 the investigation will be found, with many 

 other points of interest to New-Testament 

 students, in the article above referred to. 



INFLUENCE OF MAGNETISM ON 

 CHEMICAL ACTION.'^ 



More than a year ago I gave an account ^ 

 of some experiments which I had performed 

 with the object of determining whether mag- 

 netism exerts any influence on chemical action. 

 I succeeded in getting what appears to me to 

 be strong evidence in favor of the view that 

 magnetism does, at least in one case, exert a 

 marked influence on chemical action. The 

 principal experiment upon which this conclu- 

 sion is based may be briefly described here. 

 A vessel made of thin iron (ferrotype-plates 

 were used) was placed on the poles of a mag- 

 net, and a solution of sulphate of copper 

 poured into it. Instead of getting a uniform 

 deposit of copper on the bottom of the vessel, 

 the metal was deposited in distinctlj" marked 

 lines, the direction of which was at right 

 angles to the lines of magnetic force. Further, 

 directlj' over the poles, the deposit was uni- 

 form ; and this uniform deposit was bounded 

 by a band of no deposit, from one-sixteenth to 

 one-eighth of an inch in width. 



Since the first paper on this subject was 

 published, I have spent a great deal of time in 

 endeavoring to discover other cases of similar 

 action, and to extend the observations in vari- 

 ous directions, in the hope of reaching a satis- 

 factory explanation of the phenomenon de- 

 scribed. I shall soon give a full account of 

 the work in the American chemical journal. 

 In the mean time a condensed account is here 

 given. 



I should say at the outset, that the subject of 

 this paper has frequently been discussed and 

 experimented upon in past years. In 1847 

 Wartmann ^ summed up what had been done 

 pre\'ious to that time, and also described some 

 new experiments of his own. According to 

 him, magnetism does not influence chemical 

 action. His proof was furnished by two ex- 

 periments. In the first, the electi'olysis of 

 water was carried on in a magnetic field, and 

 the results compared with those obtained with 

 the same apparatus without the magnet. The 

 results were the same in both cases. In the 

 second experiment, iron cylinders were placed 



1 Abstract of a paper read before the National academy of 

 sciences, at its semi-annual meeting in New York, Nov. 14-17, 

 1882. 



2 American chemical journal, iii. 157. 



3 Philosophical magazine, 1847 [3], 30. 



ifi a solution of copper sulphate. Some of the 

 cylinders were magnetized, and others were 

 not. No difference was observed between the 

 deposits formed. The author calls attention 

 to the fact that his conclusion, that magnetism 

 does notinfiuence chemical action, differs from 

 that of a number of earlier writers, among 

 whom ma}- he mentioned Schweigger, Dober- 

 einer, Fresnel, Ampfere, and Robert Hunt ; 

 but that, on the other hand, it agrees with 

 that of Otto-Linnd Erdmann, Berzelius, and 

 the Chevalier Nobih. 



Among the experiments referred to by 

 Wartmann, those of Robert Hunt^ are perhaps 

 the most striking ; and to these I turned my 

 attention. Hunt states, that, when a concen- 

 trated solution of silver nitrate or of mercu- 

 rous nitrate is placed on glass over the poles 

 of a magnet, the salts crystallize out in curious 

 lines, of which an illustration is given. While 

 these experiments have no direct bearing on 

 the question whether magnetism influences 

 chemical action or not, I nevertheless repeated 

 them. To my surprise, the effects described' 

 by Hunt were not obtained. The conditions 

 were repeatedh- changed, — the strength of the 

 solutions, the strength and form of the mag- 

 nets, the thickness of the glass plates, being- 

 varied ; but under no conditions were the 

 expected effects obtained. Some of the other 

 experiments of Hunt were also repeated, but 

 only with negative results. So that even the 

 most positive statements of Hunt will require 

 verification before they can be accepted in 

 favor of his conclusion that magnetism influ- 

 ences chemical action and crystallization. 



Among- the experiments which I have per- 

 formed since the publication of the first paper 

 already referred to, may be mentioned the fol- 

 lowing : 1. The action of copper on zinc. In 

 this case the magnet evidentlj' exerted some 

 influence on the action ; causing apparently an 

 accumulation of copper on the lines bounding 

 the space directlj- above the poles. No lines 

 between the poles like those obtained when 

 copper acts on iron were observed. I am 

 unable to say positively whether the faint 

 figure observed in the zinc was due to an 

 increased deposit of copper or to a lack of 

 deposit. 2. Action of silver on zinc. Indis- 

 tinct lines were observed, which appeared 

 to be at right angles to the lines of force. 

 These were obtained only when the solution 

 of silver nitrate was quite dilute. 3. Action 

 of copper on tin. The action was evidently 

 modified by the presence of the magnet. 

 4. Action of silver on lead. No action was 



1 Philosophical magazine, 1846 [3], 281. 



