vol' XXV. i' PHILOSOPHICAL TRANSACTIONS. 360 



Hereupon I took a second glass tube, and treated it the same as the foni^er, 

 and let it lie longer, and put a little fire under the pot that was filled with sand,, 

 that I might cause the diamond-like particles to coagulate more largely. After 

 that, I poured the said aquafortis gently out of the glass tube, so as that the 

 coagulated particles might remain in it ; and then I turned the tube with the 

 orifice downwards, that all the moisture might drain out of it. 



I then viewed the tube through a microscope, and saw that there stuck a 

 great number of crystalline particles on the inside of the glass, of which several 

 were a hundred times larger than those which I had observed in the first 

 glass; I then separated, with a small copper wire, the particles that lay together, 

 in order to distinguish them the better, and saw with great amazement the 

 abovemenlioned crystalline particles, lying together like a heap of diamonds, 

 all of them as it were of a hexangular figure, and having each of them two 

 sharp hexangular points; they were of several magnitudes, and in one place 

 we saw them scattered, in another lying on a heap. In short, it would have 

 been impossible to have disposed any real diamonds before the naked eyes, after 

 uch a manner, as to exceed this phenomenon. I could not then discover, 

 among these wonderful coagulated silver particles, that had assumed a crystal- 

 line nature, any saltpetre particles: I showed them to several gentlemen, who 

 viewed them with great attention, and amazement. 



Now, to be more sure that the abovementioned coagulated crystalline par- 

 ticles were real silver, (though I made no doubt of it myself) since saltpetre 

 and copperas, from whence aquafortis is distilled, never produce such crystals, 

 at least in all observations that ever I made of them ; I took some of those 

 crystalline particles, and laid them on a piece of wood-coal, and with the flame 

 of a wax candle, which I blew upon them, put them into such a fusion, that 

 they presently became round globules, which globules were plainly visible silver. 

 I caused several of these silver crystals to be neatly drawn, which are repre- 

 sented in pi. 10, fig. 5, 6, 7, 8, 9, 10, 11, 12. 



I took again two other glass tubes, something larger than the former, into 

 which also I poured aquafortis, and then threw in some fine silver; I then 

 turned the glass tube upside down, and placed it in warm sand, that the aqua- 

 fortis might dissolve as much silver as it was capable of. After this had stood 

 some few days, and the upper part was become very clear, I poured the clear 

 water oflf from the silver, that still lay in it, into another glass tube; and turn- 

 ing the orifice downwards, I kept it in that position 14 days, almost always in 

 warm sand, to try whether the crystalline particles would not by this means 

 coagulate larger; but I could not observe that they did; and as for the 

 VOL. v, 3 B 



