606 PHILOSOPHICAL TRANSACTIONS. [aNNO 1722. 



pearances still presented themselves to his eyes; among other things, a little 

 flame seemed to dart aloft from each particle of the diamond. 



Further, he had Q small pieces of diamond lying before his microscope; and 

 in 7 of them he observed these particles, which shot forth the sparkling flames 

 as before mentioned; and in two others he could likewise observe those 

 particles, of which he supposes a diamond is composed; but they had their 

 planes turned towards the sun in such a manner, that he could distinctly ob- 

 serve several particles at the same time. 



It was an agreeable sight to behold so many appearances of sparkling flames, 

 most of them of a bright flame-colour, and some greenish : M. L. was sur- 

 prised to observe at the extremity of some of the flames such a motion and 

 vibration in the air, as if they were become so weak in that place, as not to be 

 distinguished. He was most of all surprised, that fire shot forth every way 

 out of such a particle of diamond, flashing faintly, and like lightning at a 

 distance; and this he observed several times. M. L. not only hitnself viewed 

 with his microscope the said piece of diamond, but he showed it to another per- 

 son, who aflfirmed, that the appearances exactly agreed with M. L.'s description, 

 and that he was surprised at the unusual sight. 



In another piece of diamond, the lamellae could be distinguished, of which 

 it is composed; and about I part of it consisted of so regular a pentagon, as 

 if it were artificially cut, only that a very small diamond was fastened to it, that 

 covered about the fourth part of the pentagon ; and he could plainly see that 

 it also consisted of lamellae, or particles resembling lamellae. 



Some of the pieces of the diamond, viewed with a microscope, exhibited a 

 very agreeable sight; and M. L. showed them to others, who were highly 

 pleased to observe such a variety of parts in one single piece of diamond; 

 especially that the lamellae, of which diamonds are composed, could be very 

 distinctly observed in two small pieces; viz. when these lamellae lay lengthwise 

 before the eye. 



Afterwards M. L. turned his thoughts to examine a hexagonal piece of 

 mountain crystal, whose length was about 2 fingers breadth, and its thickness 

 that of the little finger. He broke this crystal into several pieces, which he 

 placed before his microscopes, to examine whether they were composed of 

 lamellae laid on each other, in the same manner as the said diamonds acquire 

 their bulk: but after repeated trials, he could not find even the least lamellae in 

 it. But he generally found, in the 6 sides of all the pieces of crystal he had, 

 small transverse lines, some a little higher than the others. 



