26*2 Dr. Beddoes's Observations on the Process for 
did seem to contain a vestige of carbonic acid, but it was too 
minute to be appreciated. This experiment with the air was 
made after a strong white heat had been kept up for three 
hours. Soon afterwards the bubbles ceased ; but we could 
not then, nor upon examination of the apparatus when cold, 
discover any failure. The fire was still kept up for three 
hours. The tube must have been exposed to a strong white 
heat seven hours in all. The iron had lost eleven grains in 
weight. Only about one half had been thoroughly fused. The 
surface of two lumps, that had not been fused, had the close 
texture, and silvery appearance, of malleable iron. The thin 
edges yielded to the stroke of the hammer, and a gentleman, 
perfectly conversant in the nature of iron, agreed with me, 
that it had all the characters of malleable iron. 
EXPERIMENT VI. 
Thirty-one grains of artificial plumbago, in shining flakes 
from the iron works, were exposed in a small retort to a strong 
heat, for six hours, in the same pneumatic apparatus. It was 
difficult to separate, even by the help of the magnet, all the 
intimately mixed particles of iron, and there were also a few 
particles of coak incorporated with the plumbago. Air, of an 
explosive inflammable kind, was extricated, and rose freely 
through five inches of mercury. We had not been sufficiently 
careful to let the lute fix before we commenced the experi- 
ment, and it soon failed. Upon taking off the pressure of the 
mercury entirely, and repairing the lute as well as we could, 
we had every reason to believe that the air soon ceased. The 
air received in the mercury contained one-eighth of carbonic 
acid. The remainder exploded. The plumbago lost four 
