VOL. XXIV.] PHILOSOPHICAL TEANSACf IONS. QT" 



I have taken several of the shining sands and broke them to pieces ; and then 

 viewing the broken pieces through a microscope, I observed that many of those 

 small particles, though they were a thousand times less than a grain of common 

 sand, had a glance or lustre when the light fell upon them : and that several 

 such particles, and some that were larger, if viewed against the light, presented 

 a fine blooming red ; but some of them were so only in part ; from whence I 

 fconcluded that part which was not red, was thicker than the rest, and did not 

 admit light through it. Among these small broken pieces of sand, I observed 

 some that had six sides, others that were triangular ; all which are to be con- 

 sidered as common sand. I took one of the above-mentioned long slender 

 sands, which seemed to be one of the thickest, and placing it before a micro- 

 scope, it appeared as in fig. 13, nopq, in which may distinctly be perceived 

 four flat sides. I have observed in many sands, that their bodies consisted of 

 unspeakably thin scales or scaly particles. 



Among these shining sands, I discovered others that had no lustre at all, 

 neither had any of their particles, after broken to pieces, but it appeared to be a 

 dark red matter; and in other sands, so broken, there was not only a red mat- 

 ter, but even 100 shining particles, all proceeding from one sand. I have also 

 seen some sands, which, in the middle of their shining sides represented small 

 figures without lustre ; but on viewing them more narrowly, I found it was a 

 red matter, incorporated as it were in the sand. Of several sands of the coarsest 

 sort, placed before a microscope, one seemed to represent an agreeable rock of 

 stone, another a deep cavern, &c. 



These last sands were not, I suppose, so shaped from the beginning ; but 

 those cavities and protuberances which were seen, came from various chances 

 and accidents ; as by the collision of other particles of sand, which were larger 

 than these, which in their turn were again broken by other bodies of a larger 

 size, such as pebble stones, &c, 



I have split some grains of sand, and discovered figures of triangles in them. 



Soon after the cathedral church at Utrecht was almost ruined by the dreadful 

 storm, my curiosity led me to view the fallen pillars, and other parts of that 

 building that lay about ; when I observed that several of the pedestals were com- 

 posed of red stone, as also some tomb-stones ; and that in another church there 

 was a whole pillar of such stone ; on viewing some of this with the microscope, 

 it appeared to consist for the most part of large and transparent grains of sand ; 

 and that the redness of the stone was only caused by a certain red matter, which 

 had produced such a continuity or adhesion in the mass of the sand, as to be 

 able to consolidate it into a red stone. Being of this opinion, I gently separated 



VOL. V. O 



