538 PHILOSOPHICAL TKAXSACTIONS. [aNNO 1 709- 



serving it more particularly, I concluded that all those streaks or fibres, which . 

 I saw in it, were only the several coagulations or augmentations it had received 

 from time to time, and that in a very short space of time. 



Fig. 9, plate 12, represents a small particle of a little diamond, as it appeared 

 through a microscope ; in which, between a and b, as also between cdef, were 

 observed a great number of lines or fibres ; occasioned, 1 suppose, by the in- 

 crease or accession of new matter. Now that the increase of diamonds is made 

 in such a manner, we may conclude the rather, because we know that the 

 same thing happens in the coagulation of many salts. I have several times 

 taken some of these particles, and laid them on burning wood coals, until 

 they were red hot, and in that condition thrown them into the water, to see 

 whether they would burst to pieces, or whether there would be any separation 

 of matter from them ; but that never happening, I must conclude that there 

 was no air nor any moisture shut up within them. 



One particle of a diamond appeared to the sight, as fig. ]0, after I had made 

 it red hot, and slaked it in water several times ; in which also, between l and 

 G, are. several small streaks or fibres: and when I observed it the last time, 

 alter 1 had taken it out of the water, it appeared, between lght, as if some 

 small scales had been separated from it; just like the shining or glittering parts 

 often seen in some stones, and particularly in the great flint-stone brought in 

 ship^ from Greenland for ballast, when the whale-fishing is not good, when its 

 crystalline or diamond transparency is gone. 



Fig. 1 1, represents also a particle of a diamond, as it appeared through the 

 microscope, after it had been made several times red hot, and thrown into cold 

 water; in the middle of which one might perceive such slits or cracks as 

 might be compared to the top or ceiling of an unwainscotted church within 

 side, but could not be so well traced by the painter as it ought to have been ; 

 but whether this appearance be natural to the diamond, or whether it proceeds 

 from the breaking it in pieces, is unknown to me ; but my opinion is, that it 

 was not occasioned by its being made red hot, and thrown afterwards into the 

 water ; for if so, the diamond would have been separated into a great many par- 

 ticles, or there would have been several cracks or flaws in it. 



Fig. 12, represents the small particle of a diamond, no larger to the naked 

 eye than a small grain of sand, from whence we may judge also of the size 

 of the other diamond particles, represented by the former figures. We may 

 also observe, at sttwy, the sharp points of the said particle. From whence I 

 conclude, that I was right in my former remarks concerning the particles of 

 sand ; viz. that the said very small particles consisting of regular points, and 

 being smooth sides like diamonds, they were soft at their first coagulation, 



