THE 

 LONDON, EDINBURGH and DUBLIN 



PPIILOSOPHICAL MAGAZINE 



AND 



JOURNAL OP SCIENCE. 



[FOURTH SERIES.] 



FEBRUARY 1862. 



XIII. On the Cause of Vesicular Structure in Copper. 

 ByW. J. Russell, Ph.D., and A. Matthiessen, F.R.S.* 



ALL specimens of commercial copper, when carefully ex- 

 amined, are found to be more or less vesicular in their 

 structure : in some cases the vesicles are so small as to require a 

 magnifying glass to see them, but in other specimens they are 

 developed on a much larger scale. Copper and silver are, we 

 believe, the only metals which may readily be made to assume a 

 vesicular structure. In the case of silver, it is well known that 

 the fused metal absorbs oxygeu, which being again given out on 

 cooling, produces the vesicular structure. It appeared therefore 

 possible that the vesicular structure in copper might also be 

 caused by the absorption of some gas. Our experiments have, 

 however, proved this not to be the case, but have led us to the 

 same conclusion with regard to the cause of this porous struc- 

 ture as that arrived at by Mr. Dickf. As, however, our experi- 

 ments on some points have been rather more extended than his, 

 and remove, we believe, all doubt from the subject, a short 

 account of them may not be without interest. 



The amount of gas contained in these cavities found in copper 

 was evidently too small to allow of its being collected, we were 

 therefore obliged to carry on the investigation synthetically. It 

 seemed, however, probable, from the inside of the cavities always 

 appearing untarnished, that they did not contain any oxygen. 

 In order, then, first to ascertain whether the vesicular structure 

 was owing to any mere absorption of a gas by the melted metal, 

 we passed each of the ordinarily occurring gases, carefully purified 



* Communicated bv the Authors, 

 t Phil. Mag. June 1856. 



Phil. Mag. S. 4. Vol. 23. No. 152. Feb. 18G2. G 



