(18 
'nil'] IION. SIR CITARLES ALGERNON LARSONS; EXPERIMENTS ON 
up to 15,000 atmospheres, wliicli produced soft graphite, and an experiment where a 
carl)on crucible, containing iron previously heated and carburized in the electric 
furnace, was quiclcly transferred to a steel die, and while molten and during cooling 
subjected to a pressure of 11,200 atmospheres, the analyses showing less crystalline 
residue than if tlie crucible had been cooled in water. 
It was also emphasized that the pressure of 11,200 atmospheres must be greater 
than could be produced in the interior of a spheroidal mass of cast iron when 
suddenly cooled, and that the inference from these experiments was that mechanical 
])ressure is not the cause of the production of diamond in rapidly cooled iron, as had been 
supposed by jMoissan. This conclusion appears to us in the liglit of our more recent 
experiments to be one of great importance, and it will be further discussed in this paper. 
It may be well to state that, in order to flxcilitate a clearer view of the bearing of 
each experiment on the subject, they are not placed always in chronological order. 
1 he difficulty of ensuring satisfactory experiments and the elusive character of the 
analyses must be the excuse for the random character of some of the former. The 
great majority of the experiments v.nre failures as regards results, but a few have 
gi^en information that Avas scarcely anticipated when they were deA’ised. 
