Attempts to make Diamonds 2 1 1 



topaz, and was soluble in hydrofluoric acid. Thus it was 

 not diamond. 1 He had repeated the experiments with 

 Mr. Mactear at the British Museum on a large scale, devoting 

 some days to the work. A crystalline dust was the result, 

 which was not soluble in the above-named acid, but it 

 proved to be so ultimately in other reagents ; Mr. Mactear 

 himself was now satisfied that he had not succeeded in 

 producing a diamond. 



Mr. Moseley exhibited some microscopic sections of corals 

 received from Dr. G. von Koch, of Darmstadt. To prepare 

 them the corals were first hardened in absolute alcohol ; 

 then soaked in a solution of gum sandarach, copal, or Canada 

 balsam in absolute alcohol, after which they were allowed 

 to dry slowly. Sections are then cut with a fine saw and 

 rubbed down in the usual manner. The method can 

 probably be adopted in very many cases where a soft tissue 

 is associated with a hard skeleton. 



Feb. 26th, 295th meeting. Professor Maskelyne, referring 

 to Mr. T. B. Hannay's claim to have produced artificial 

 diamonds, said that he had received some specimens from 

 him. They were diamonds, but not all of them were com- 

 plete crystals, and it had been doubted, especially by 

 Professor Roscoe, to whom Mr. Hannay had sent specimens, 

 whether he had really made them. One of the specimens, 

 which Professor Maskelyne had examined, had every 

 appearance of being a fragment from a natural diamond 

 crystal much larger in size, and all of them were a minute 

 dust. Mr. Hannay had not yet entirely explained the 

 process, 2 but very great pressure (some 2000 atmospheres) 

 and a rather, but not extremely, high temperature were 

 essentials ; the materials employed apparently being an 

 alkaline metal, such as sodium or lithium, and a hydro- 

 carbon, associated with a nitrogenous compound containing 

 carbon that was sufficiently stable under the circumstances 



1 A more detailed account of his experiments is given by Professor 

 Maskelyne in Nature, vol. xxi. page 203. 



2 Mr. Hannay gave a fuller account in a paper read before the Royal 

 Society, " On the Artificial Formation of the Diamond," Proc. Roy. Soc. 

 vol. xxx. page 450, and in a communication to Nature, vol. xxii. page 255. 



