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IS3 



opportunities as he had ; and it was one in which he wished to excite 

 an interest. He had himself certainly ascertained that thin fissures in 

 flint were filled up with a kind of chaldeonic deposit, which was cer- 

 tainly of a more recent date. Pure blue films of chalcedony w«re 

 constantly found in flints. 



Mr. W. SAUNDERS said he did not know whether Mr. Pankhurst 

 had observed that crystals had the power of replacing damaged 

 angles . 



Mr. Pankhjjrst replied that if the angle of a crystal were broken 

 off while in the solution in which it had been formed, it rebuilt the 

 damaged part with the same wonderful straightness and precision of 

 angle which it originally had. The damage was as completely 

 obliterated as, in course of time, was a slight cut upon the body. 



Mr. F. Merrifield : Will there be a scar left ? 



Mr. Pankhurst said that very often no appearance of the re- 

 building could be noted ; but that sometimes there would be where 

 probably the solutions had differed in power. 



Mr. B. LOMAX said he remembered that, when at the gold 

 diggings, it was always a problem, in days past, as to how best to 

 e-xtract gold and other substances, including silica, from quartz, at the 

 least possible cost, and with the least possible labour. He was now 

 anxious to know what form the smooth, hard, and transparent coating 

 took which covered grassy plants. 



Mr. Haselwood said that Dr. Carpenter informed them that the 

 vegetable bark of grasses might be burned away, and that the silica 

 would then remain in threads. 



Mr. C. F. Dennet said silica was a component part of almost 

 everything in Nature, and was a source of great trouble to the 

 manufacturing merchant, who had to get rid of it from the raw 

 material out of which stuffs and paper were manufactured. 



Mr. Merrifield asked— Supposing silica, in the gelatinous form, 

 found its way into a cavity in sufficient quantity to fill it, when that 

 which distinguished the gelatinous silica from flint was parted from it 

 so that nothing but flint remained, what proportion of the cavity would 

 be represented by flint .'' 



