Observations upon M. Boutigny’s recent Experiment. 247 
following up a fertile idea, I then acquired an impression 
that it referred to a law of nature which was by no means 
completely revealed, and in which opinion I was further 
strengthened by the report of his last experiment. In con- 
Sequence of an oral communication of this experiment, M. 
Fessel wrote to me from Cologne, stating that, on the follow- 
ing day, he had dipped his finger into lead heated to its 
highest point, by which means the projecting portion of the 
nail of the finger had been burnt, but, in other respects, the 
finger remained perfectly uninjured ; he also stated further, 
that a workman in the employ of Messrs Behren and Co. 
manufacturing-engineers at Cologne, had made the experi- 
ment with melted iron, and would repeat it before me. I 
therefore accepted the offer, and, accompanied by several 
persons interested in the matter, proceeded to Cologne. The 
workman, in my presence, struck the unmoistened extremi- 
ties of his fingers rapidly, and not without fear, against the 
surface of the iron which had just flowed from the melting 
furnace into a trough, and which was afterwards used in 
casting a large plate for a furnace. I was thus convinced of 
the perfect truth of Boutigny’s experiment: and whilst care- 
fully examining the extremities of the workman’s fingers, one 
of the two assistants of the Physical Cabinet accompanying 
me, struck the entire surface of the open hand, which he had 
previously dipped in water, so strongly against the bright red 
surface of the iron that some of the fused metal was ejected ; 
the other assistant, immediately afterwards also, struck it 
with his moistened hand. After these experiments, which 
were made in opposition to Boutigny’s precautions not to 
strike the mass, experiments which, for the sake of precau- 
tion, I wished to make before the immersion became unne- 
cessary; I moistened my right hand, inserted the index- 
finger almost completely into the melted mass, and moving 
it very slowly through it, withdrew it in two seconds ; at the 
same time I felt how the iron moved before my finger, but 
did not experience the slightest sensation of heat.* 
* More than twenty years ago Professor H. Rose, in visiting the foundries at 
Avestad, in Sweden, saw a workman, for a small reward, take melted copper 
