THE ARTIFICIAL PRODUCTION OF DIAMOND. 
83 
residue generally resulted from the small iron globules, and also from the dust, but 
never anything from the ingot remaining in the crucible. 
In several experiments water was admitted, which played directly on the crucible, 
the upper carbons resting on the rim prevented its upsetting by the force of the 
water, and still there was no residue. In one experiment the carbons were lifted and 
the charge flowed out, forming spherules of varying size in the water. There was a 
very small diamond residue from these spherules. 
In one experiment a crucible was filled with iron and carbon and closed by a tight 
carbon cover, a hole bored in the side of the crucible, a massive block of iron placed 
Fig. 11. 
close opposite the hole and the crucible boiled, the vacuum being under 1 mm. No 
crystallised residue was found in the deposit on the iron block from this high 
velocity jet of vapour of iron and carbon. 
In another experiment a powerful electro-magnet was provided with poles to give 
a concentrated field, and an arc struck between two carbons, arranged to burn 
within this field and regulated from without by hand. There was an iron block 
upon which the arc directed by the field could play and condense its carbon vapour. 
The analysis gave no diamond. 
VOL. GCXX.-A. 
N 
