304. JoLty—On the Volume Change of Rocks and Minerals attending Fusion. 
the coexistence of the last-mentioned of M. Moisson’s conditions along with the 
first two. 
In a recent number of Natwre (September 23rd, 1897), it appears that the 
artificial production of diamond has now been accomplished under the action of | 
the first two conditions only. This appears to confirm the idea that the process 
of the formation of diamond by artificial means may be regarded as a case of 
crystallographic reversibility. It will probably turn out before long that this 
matter will possess an important commercial bearing, as well as being of consider- 
able scientific interest. 
September 30th, 1897. 
