ARTIFICIAL DIAMONDS. 
141 
finding that some of the carbon which was set free actually 
crystallized in the form of diamond ! 
This adamantine carbon has been severely tested, not only 
by the discoverer himself, but also by so high a mineralogical 
authority as Professor Maskelyne. First, as to hardness , which 
of all characters is the most characteristic and the most valuable 
in diamonds : it is found that Mr. Hannay’s crystals will easily 
scratch deep groves in a sapphire, and no substance save 
diamond possesses this strong abrading power. With regard 
to crystalline form , little can be said, but still that little is quite 
satisfactory. Perfect crystals have not, as yet, been obtained, 
and the fragments look like splinters of diamond rather than 
crystals. Still in one case Professor Maskelyne found traces of 
the distinctive octahedral cleavage, and Mr. Hannay has called 
attention to the curvature of some of the faces, so suggestive of 
diamond-crystals. Optically the crystalline fragments behave 
themselves just as diamonds might be expected to behave. 
Moreover, when placed in the scales they are not found 
wanting, for some of the artificial adamantoid carbon has as 
high a specific gravity as 3 5. Finally, the chemical tests leave 
nothing to be desired. Heated in the voltaic arc the carbon 
swells up and turns black, just as is the case with diamond ; 
while if burnt in the usual way, in oxygen, it yields only 
carbonic acid ; and though but a very small quantity was 
operated on, the result showed that the artificial crystalline 
body contained as much as 97*85 per cent of carbon. All the 
lines of evidence therefore converged to this point, that we are 
here dealing with a substance which is to all intents and pur- 
poses neither more nor less than diamond. 
It thus appears that Mr. Hannay has mimicked Nature so 
successfully as to produce a body not distinguishable from the 
natural gem. In connexion with this interesting discovery, 
however, two questions naturally suggest themselves : first, has 
the artificial substance been produced in the same way as the 
native diamond ? And, secondly, can the artificial product be 
made in such quantity and with such facility as to be profitably 
sent into the market P 
The first question is by no means easily answered. Nature 
has such a wealth of resource at her command that in com- 
passing a particular end she is by no means limited to a single 
method. Nothing is more likely than that the diamond has 
been formed in one way in this locality and in another way in 
that. In fact, the conditions of its occurrence are so dissimilar 
in different parts of the world as to make it highly probable 
that the diamonds of Brazil and the diamonds of South Africa 
have been brought forth by different processes. Mr. Hannay 
may or may not have hit upon an exact imitation of the natural 
