538 shilosophical transactions. [anno 1693. 



brimstone ; but on examination I could not find that the inflammable parts were 

 true brimstone. I then caused the flowers of brimstone to arise, and viewing 

 them, found, among several irregular parts, some globules transparent like oil ; 

 and the higher they rose from the fire, the smaller were these globules, till in 

 the end they became undistinguishable. The volatile parts of cinnabar could 

 not be driven very high, though with a great fire, whereas those of brimstone 

 were raised much higher with a small heat. I observed in the brimstone several 

 salt particles, constituted, as I guessed, of many small united globules. For I 

 suppose they were raised in a round figure, which subsiding shoots into angles, 

 especially if they meet with any moisture. 



Powdering some cinnabar, I exposed it to the fire as before, and found there- 

 in six-sided figures, with some triangular ones, whereof some had one, others 

 more angles broken ofi^; with other different figures with one acute angle, but 

 there were no squares or oblongs. I then poured rain water on some of this 

 cinnabar that had been raised by the fire without flaming; and when it had stood 

 in the air till part was evaporated, I found a great number of salt particles of a 

 longish figure as are represented fig. 7j !• Among the rest some were pyramidal, 

 constituted on a six-sided basis, and ending in a point like little diamonds. 

 There were salts of some other figures, as oblongs, &c. So that no estimate 

 can be made of these salts. I then poured rain-water on beaten cinnabar, and 

 after some weeks settling, and in part evaporated, I found in it an inconceivable 

 number of salt particles, too small to discern their figures, my best microscope 

 showing them no larger than a sand appears to the naked eye ; only I fancied 

 some were sexangular. Boiling some of this water, and evaporating part of it, 

 the salts were to be seen in greater quantity ; some of the largest are repre- 

 sented, magnified, as K L L. 



I took several clean phials, from 3 to 6 inches long, which I heated, to dry 

 them and rarefy the air; and then put in them one or more of the largest corns 

 of gunpowder, and closed them up to exclude the common air, and placed them 

 in so great a heat that the powder took fire, filling the glass with a white smoke, 

 some of the coal and brimstone sticking to the sides ; but putting in more 

 corns, they were carried up much higher, so that I could very distinctly discern 

 the brimstone from the nitre ; for it lay so thick in some places, as to exhibit a 

 yellow colour, and might by a good microscope be seen moving circularly in the 

 white smoke, which was the nitre. I then laid the glass along, that the parti- 

 cles of the nitre might be distinct from those of the coal and brimstone; and 

 then I found those particles which before seemed globular, were, when fixed on 

 the sides of the glass, all shot into six-sided salts. Some were like fig. 8, M, N, 

 with others irregular as O, and some of these ended pyramidally like little dia- 



