424 Mr. Fox on the change in Minerals ly Galvanism. [April 



electricity ; for, can it now be doubted, that rocks impregnated with or 

 holding in their minute fissures different kinds of mineral waters, must 

 be in different electrical conditions or relations to each other ? A gene- 

 ral conclusion is, that in these fissures metalliferous deposits will be 

 determined according to their relative electrical conditions ; and that the 

 direction of those deposits must have been influenced by the direction 

 of the magnetic meridian. Thus we find the metallic deposits in most 

 parts of the world having a general tendency to an E. and W. or a N.E. 

 and S. W. bearing. Mr. Fox added, that it was a curious fact, that on 

 submitting the muriate of tin in solution to voltaic action, to the nega- 

 tive pole of the battery, and another to the positive, a portion of the 

 tin was determined like the copper, the former in a metallic state, and 

 the latter in that of an oxide, showing a remarkable analogy to the 

 relative position of tin and copper ore with respect to each other as 

 they are found in the mineral veins. 



The Chairman (Dr. Buckland) said, it had been observed to them last 

 evening, that the tests of some of the highest truths which philosophy 

 had brought to light was their simplicity. He held in his hand a black- 

 ing-pot, which Mr. Fox had bought yesterday for a penny, a little water, 

 clay, zinc, and confer ; by which tumble means he had imitated one 

 of the most secret and wonderful processes of nature, her mode of mak- 

 ing metallic veins. It was with peculiar satisfaction he contemplated 

 the valuable results of this meeting of the Association. There was also 

 a gentleman now at his right hand, whose narrie he had never heard 

 till yesterday, a man unconnected with any Society, but possessing the 

 true spirit of a philosopher ; this gentleman had actually made no less 

 than 24 minerals, and even crystalline quartz. He (Dr. B.) knew not 

 how he had made them, but he pronounced them to be discoveries of the 

 highest order : they were not made with a blacking-pot and clay, like 

 Mr. Fox's, but the apparatus was equally humble ; a bucket of water 

 and a brickbat had sufficed to produce the wonderful effects which he 

 would detail to them. 



Artificial Crystals and Minerals. — A. Crosse, Esq., of Broomfield, 

 Somerset, then came forward, and stated that he came to Bristol to be 

 a listener only, and with no idea that he should be called upon to ad- 

 dress a Section. He was no geologist, and but little of a mineralogist; 

 he had however devoted much of his time to electricity, and he had 

 latterly been occupied in improvements in the voltaic power, employing 

 a battery which he had succeeded in keeping in full force for twelve 

 months by water alone, rejecting acids entirely. Mr. C. then proceeded 

 to state that he had obtained water from a finely crystallized cave at 

 Holway, and by the action of the voltaic battery had succeeded in pro- 

 ducing from that water in the course of ten days numerous rhomboidal 



