VOL. XV.] PHILOSOPHICAL TRANSACTION*. 187 



ceived I saw more in a quantity of water equal to the weight of a grain, than 

 there are stars to be seen in the heavens by the naked eye. 



Salt of Wormwood. — In salt of wormwood, after being dissolved in water, 

 were presently discovered a great quantity of figures, sharp at both ends ; as 

 N° 2, fig. A. Again, there were lesser figures, as B, in innumerable quan- 

 tities : some few had six sides, as C ; a few were flat and square, as D ; a very 

 few were like triangles, which had the angles cut off; as E. Where the water 

 had continued long, there were several six-sided figures, ae large as a small 

 sand ; as, among the rest, F. Also some square pieces of salt, like a looking 

 glass with a border about it, as fig. G. 



Alum. — Having put some alum in rain water, it exhibited very small figures, 

 with hexagonal bases, and sides rising up pyramidal, like a pointed hexangular 

 diamond, as N" 3, A A A. They were of different magnitudes, and some 

 seemed plain, without any rising, as B B. There were also six-sided figures 

 irregular, as C and D. But as the water evaporated, there were seen several 

 long blocks of alum, as fig. E ; and the salts run together, as large as sands, 

 growing unmeasurably, where the water had been thickest, so as thereby to 

 be less distinct. There were also six-sided flat figures, as F, having in the 

 middle other small six-sided figures, rising pyramidally. 



Salt-Petre. — I put salt-petre in water, and observed swimming in it a few 

 long particles, which seemed to have no thickness, as N" 4, fig. A. These 

 increased visibly in size, though I could not perceive any particles near them 

 that could cause it. As the water in any place began to be evaporated, I found 

 many figures whose bases were square, and rising into pyramids. There were 

 also a few triangular figures. Where the water lay thick, there were pretty 

 figures like square sticks, as CDE. These last figures took up no greater 

 space than might have been covered with a great sand ; though there were 

 clusters of them, that were 1 00 times less. 



Vitriol of Cyprus, or Blue Vitriol. — Having dissolved blue vitriol of Cyprus in 

 fair rain water, and viewed it in a microscope ; I found swimming on the water 

 clear pellucid figures, like crystal ; these had no thickness to be discerned in 

 them, because they were level with the surface of the water ; all their ends 

 were sloping, as N° 5, fig. A. In 2 or 3 minutes of time, they grew 100 

 times larger than before ; though they continued to have the same shape, for 

 they increased both in length and breadth ; but in becoming bulky, they lost 

 their pellucidness, and turned of a blue colour : other salts were shorter, and 

 shaped like B, some of them so small, that by calculation they were abore 

 28,000 times thinner than a hair of my head. As I spread the water very thin^ 

 the figures were inconceivably strange : it seemed that the vitriol separated from 



BB2 



