rot. XV.] PHILOSOPHICAL TRANSACTIONS. JQl 



some are larger, and these either transparent or more obscure, of which last I 

 shall describe two, as G and H, which appeared plainly to be compounded of 

 other figures ; for in one of the sides of G, I counted more than 30 figures, 

 which number being cubed, comes to near 30,000 : and yet the side of G 

 seemed not to be the 40th part of the diameter of a coarse sand. 



Salt of English Soda, — I took of this soda, (which is made of glass wort, 

 and is much used by the potters in our city, for glazing their porcelain) and 

 beat it small, and then put it into rain water ; when it was settled, I observed 

 in the water long thin figures, whose ends seemed sometimes to be straight 

 lines, and other times circular, as N° 14, fig> A. As the figures increased in 

 size, they became more straight at the ends, and not flat or plain, but generally 

 raised, as fig. B. Some were raised, but their ends consisted of 3 sides ; and 

 some were even at one end, and had 3 sides at the other end, as C. There 

 were also 6-sided small figures, as D ; and of these I discovered a great number 

 completely formed, very thin and small, and clear as crystal ; whereas the 

 other figures were obscure, as if they had been strewed with blackish sand; and 

 so likewise were these, when they were viewed with a better glass. I saw also 

 figures which were broad in the middle, and sharp at both ends ; or rather a 

 little flat, as E. Also small squares, as F ; and this was the most general figure 

 of this salt ; for'the bases were mostly square; running up into a pyramid, like 

 common salt. I took some pains to find of what kind of parts B, C, D, and 

 E, were compounded, and it seemed to me, that each of them consisted of 

 parts like itself, yet I once observed that a six-sided figure like D had joined it- 

 self to one like E. 



When the soda had lain long in the water, and this was become very strong, 

 there appeared in it a great many transparent figures, like the fairest crystal ; 

 these had their sides perfect, their breadth and thickness equal, shaped as B, C, 

 and D. 



Salt of Soda of Brittany. — Having treated this soda as the former, I saw 

 floating in the water an incredible number of small 6-sided figures, as N° 15, 

 fig. A ; being very thin, and many of them so little, that I could not have de- 

 scribed them, if some of them had not been larger than the rest. In another 

 place, I saw large 6-sided planes, made like hexagonal looking glasses, and 

 having a small 6-sided figure on the surface, as B. I saw also a few figures 

 formed like C, and some squares, as D, part of them plain, and others had the 

 sides rising up pyramidally to an obtuse point, as E, or rather a pyramidal 

 frustum, as F : for the top is the true figure of the salt, and the rest of the 

 bulk is nothing but an addition of other quadrilateral salts. Likewise would 

 the top of G, if magnified, be like to H. 



