ARTIFICIAL DIAMONDS. 
137 
into another ; all that we attempt is, to bring the given kind of 
matter into such a physical condition that it shall possess the 
set of properties which we so highly prize in the diamond. 
About a century ago the chemical composition of the 
diamond was first carefully determined, and a fresh light was 
then cast upon the gem. From the day when it was ascertained 
that the diamond consisted only of carbon, its artificial pre- 
paration came within the range of possibility. The old 
notions of its kinship were entirely changed, and it was un- 
expectedly found that such vulgar substances as blacklead and 
charcoal could claim close relationship with the costly gem. 
Pliny ridicules the idea that the diamond could be found, as 
Metrodorus Scepsius had affirmed, in a locality ‘ wherein amber 
is engendered ; ’ and the old philosopher does not hesitate to say 
of this authority, ‘howbeit no man doubteth that he lieth 
stoutly.’ But, after all, this notion of the relation of the 
diamond with amber is more sound, from a chemical point of 
view, than Pliny’s own notion that diamonds ‘ breed not but in 
mines of gold.’ 
Knowing the chemical composition of the diamond, the 
mystery of its formation resolves itself into this problem : 
How to crystallize a given piece of carbon in the special 
forms which the gem possesses, and with the accompanying 
transparency, lustre, and hardness? Difficult as the solution 
may seem, men of science have long believed it to be practi- 
cable. ‘We are so sanguine about this matter,’ said Dr. Percy, 
when lecturing on chemical geology in 1864, ‘ that we cannot 
refrain from believing that one day or other the thing must be 
done. It assuredly will be done. We have apparently been very 
near it from time to time, but have never yet reached it.’ 
These prophetic utterances have recently received a most un- 
expected fulfilment, which it is the purpose of this article to 
chronicle. 
About three months ago, Mr. James Mactear, of the St. 
Pollox Chemical Works at Glasgow, created considerable excite- 
ment by announcing that he had succeeded in producing a 
crystallized form of carbon, comparable, if not identical, with 
diamond. It is acknowledged that this gentleman brought 
extensive chemical knowledge to bear upon the subject, and 
that he struck out a most promising line of research. Never- 
theless, his announcement was confessedly premature ; and it 
remains doubtful whether anything that can fairly be called 
diamond was ever produced in his researches. At any rate, 
the small crystalline particles which were at first taken to be 
diamonds, gave a most unsatisfactory account of themselves 
when subjected to Professor Maskelyne’s searching examination, 
