or the pretended Phenomenon of Incomhtstilility . 53 



iieved myself in a state to give the following explanation of 

 the phaenomena which I had seen executed by Senor Lionetto. 



I. The hair over which he passed the plate of red-hot iron 

 had been first bathed in a solution of alum or in sulphu- 

 rous acid, substances with which it was still wet even at the 

 moment when touched with the iron. Hence the origin of 

 the vapour which arises from his hair in this experiment. 



II. The plate of red-hot iron with which he rubbed his 

 leg and arm produced no alteration, because those parts were 

 prepared with the substances of which I have spoken. 



III. The same reason will explain the phaenomenon of 

 the stroke which he wave the red-hot iron with his foot, al- 

 though the contact of the iron in this experiment was longer : 

 but it is not difficult to comprehend how the sole of the foot 

 may he conveniently prepared for this purpose, by the above 

 or similar substances, it being in its nature the most callous 

 and least sensible part of the body. The contact however of 

 his foot with the plate of red-hot iron was certainly not of 

 very long duration ; on the contrary, it clearly appeared in 

 this experiment, more than in any other, that his incom- 

 bustibility did not surpass a certain limit, beyond which he 

 might be burned, and like others was highly combustible. 



IV. With regard to the boiling oil; this phenomenon, as 

 being the most striking in appearance, merits a more mi- 

 nute examination. To understand well such a fact, it is 

 necessary to know the following particulars. Senor Lionetto 

 took the inflamed oil from the fire, and, to give the public a 

 proof of its high temperature, immersed in it a certain por- 

 tion of lead, which melted, thereby demonstrating to what 

 degree it was heated. To me it appears that such an artifice 

 should contribute to cool the oil : this is clearly manifested 

 by the known laws of caloric, the greater part of which is 

 employed in the fusion of the lead. I was better convinced 

 of this truth in repeating the same experiment with a ther- 

 mometer in my hand, which after the fusion of the lead fell 

 most sensibly. Of all the oil thus reduced to this tempera- 

 ture, he took barely a quarter of a spoonful ; and this quan- 

 tity he dexterously made to fall on his tongue only, which 

 was perhaps prepared in such a manner that it cooled in an 



P 3 instant 



