VOL. XXXir.] PHILOSOPHICAL TRANSACTIONS. 605 



On the Particles and Structure of Diamonds. By M. Leuwenhoeck, N^ 374, 

 p. 199. Translated from the Latin. 



After M. Leuwenhoeck had discovered, that some metals, and even grains 

 of sand, consisted of very small particles of the same matter, he turned his 

 thoughts to consider a diamond, as whether it also consisted of the same sort 

 of particles, that might be observed with the microscope. 



Therefore viewing, with a microscope, a small diamond, he could observe 

 with the naked eye a great many particles in the unpolished and dark part of it; 

 and he found, that it consisted of small particles: but not being satisfied with 

 these observations, he resolved to break a diamond into pieces, to consider 

 these the better. 



Laying, therefofe, a diamond upon a hammer, he struck it twice with an- 

 other hammer, by which it was broken into 4 or 5 pieces: with which not being 

 yet satisfied, he had a mind to break the diamond into still smaller bits, and 

 accordingly he folded up a piece, larger than the rest, in a double piece of 

 paper, that he might not lose any of it. 



Here M. L. was surprised at the hardness of a diamond ; which, though 

 often struck with considerable force, broke only into 4 or 5 pieces, without any 

 small bits. 



On placing the last mentioned pieces before a microscope, he viewed them, 

 and found that they all consisted of very small particles: and on exposing them 

 to the rays of the sun, he observed a kind of little flame break out from them, 

 and larger than any he had ever observed. 



He observed with his naked eye one small piece that had its flat and square 

 crack directly exposed to the sun; and as far as he could judge with his naked 

 eye, 3 or 4 hairs of a man's beard in breadth. Such a quantity of sparkling 

 flames issued from this piece of diamond, that he judged them upwards of 400: 

 a few of those flames lay closer to each other, and were larger than the rest: 

 whence he concluded, that the particles of the diamond were larger in that 

 place, and more regularly disposed than the other particles. 



Afterwards he viewed another piece of diamond, about the same size as the 

 former, which was also directly exposed to the rays of the sun; and he found 

 it consisted of the same number of very small particles : from the half of that 

 little piece there likewise arose the same sparkling flames, but smaller; and in 

 the other half a kind of waving flame was observed, with a continual corusca- 

 tion, like a faint lightning. 



Also, after withdrawing these little pieces out of the sun's rays, various ap- 



