Mr. R. W. Fox on Pseudomorphous Crystals of Quart z. 5 



distributed itself over the copper plate. In a short time, pre- 

 cipitation increasing, two curious curved spaces were formed 

 by the fine deposit, proceeding from one pole towards the 

 other in opposite directions, increasing in width as they pro- 

 ceeded, until they were abruptly checked at a little distance 

 from the poles towards which they were directed ; these spaces 

 being very distinct from the first formed curved lines. Fig. 

 10 represents this very interesting arrangement. 



These experiments are sufficient to show that magnetism 

 exerts a powerful influence on molecular arrangements, and 

 that it regulates the direction of crystalline formations. I 

 hope to be enabled to pursue this interesting inquiry still 

 further ; it has most important bearings on many of the great 

 phaenomena of nature, and I am therefore anxious thus early 

 in my inquiry to call attention to the singular and conclusive 

 results which I have obtained. 



I have the pleasure of remaining, 



Dear Sir, yours truly, 



6 Craig's Court, Dec. 10, 1845. Robert Hunt. 



II. On certain Pseudomorphous Crystals of Quartz. 

 By Robert Were Fox, Esq.* 



I SUBMIT to the Society's notice some specimens of 

 quartz, with pseudomorphous octahedral crystals of the 

 same substance, which appear to me to possess a sort of hi- 

 storical interest, or at least to indicate that a succession of 

 changes must have occurred in the condition of the mineral 

 vein from which they were taken. They were found b}' S. 

 Peters (dealer in minerals) in one of the heaps of vein stones, 

 at the Consolidated Mines, and I understand were broken from 

 a copper vein in " killas" at the depth of. about 160 fathoms 

 below the surface. He observed that many of the crystals 

 contained water, and he secured some of it for me, by carefully 

 breaking some of them. This he did mostly in my presence, 

 and we had considerable difficulty in collecting even very small 

 portions of the liquid in different phials. Two of these por- 

 tions were nearly tasteless, or saline in a very slight degree, 

 as far as I could judge from a single drop of each. In both 

 common salt was detected, and nothing else in one of the por- 

 tions; but the other, when evaporated, left minute needle- 

 formed crystals, which I was prevented by an accident from 

 examining. The third portion of water was much more in 



* Read at a meeting of the Cornwall Polytechnic Society, on the 8th of 

 October, 1845, and communicated by the Author. 



