301 



10000 



The most remarkable peculiarity of the Calton Hill anthracite, as 

 appeal's from the results given above, is the large proportion of sul- 

 phur it contains, amounting to nearly 3 per cent. Sulphur has 

 been supposed to occur in the different varieties of coal in combina- 

 tion with iron, as pyrites, but the trace of that metal present in the 

 Calton Hill anthracite is so small, that the sulphur must have been 

 combined with the organic constituents of the mineral. 



Note on the Crystallisation of Carbon, and the possible derivation of 

 the Diamond from Anthracite and Graphite. By Dr George 

 Wilson. 



The author stated that the object of his communication was, to 

 suggest the possibility of anthracite as well as graphite being sub- 

 stances from which the diamond is developed. After referring to 

 previous theories, as all assuming that carbon must have been fluid 

 or semifluid, before it crystallised, he stated that his hypothesis 

 contemplated the possibility of graphite, as well as amorphous car- 

 bon, and its solid combinations, such as anthracite, undergoing crys- 

 tallisation into the diamond, without losing their solidity during the 

 change. He thought anthracite more likely than most substances to 

 yield the diamond, for the following reasons: — 



Firstly, As it occurs in nature, in many localities, it is found pass- 

 ing by insensible gradations, on the one hand, into common coal, on 

 the other, into graphite ; so that it may be regarded as representing 

 the transition-state from fossilised vegetable matter to pure carbon, 

 and as tending, under the influence of certain agencies, to change 

 ultimately into the latter. 



Secondly, The chief element of anthracite is carbon, of which it 

 frequently contains 91, and sometimes 95 per cent. 



Thirdly, Its other ingredients (with the exception of the ash, 

 which is often under ouo per cent.), namely, hydrogen, oxygen, nitro- 

 gen, and sulphur, form volatile compounds with each other, and with 



