POPULAR FALLACIES. 



A kettle which lias a metal handle cannot be touched, wheiu 

 filled with boiling water, without a covering of some non-con- 

 ducting substance, such as cloth, or paper, while one with a 

 wooden handle may be touched without inconvenience. 



13. The feats sometimes performed by quacks and mounte- 

 banks, in exposing their bodies to fierce temperatures, may be 

 easily explained on the principle here laid down. When a man 

 goes into an oven, raised to a very high temperature, he takes 

 care to have under his feet a thick mat of straw, wool, or other 

 non-conducting substance, upon which he may stand with impu- 

 nity at the proposed temperature. His body is surrounded 

 with air, raised, it is true, to a high temperature, but the 

 extreme tenuity of this fluid causes all that portion of it in con- 

 tact with the body, at any given time, to produce but a slight 

 effect in communicating heat. The exhibitor always takes care 

 to be out of contact with any good conducting substance ; and 

 when he exhibits the effect produced by the oven in which he is 

 enclosed, upon other objects, he takes equal care to place them 

 in a condition very different from that in which he, himself, is 

 placed ; he exposes them to the effect of metal or other good 

 conductors. Meat has been exhibited, dressed in the apart- 

 ment with the exhibitor ; a metal surface is, in such a case 

 provided, and probably heated to a much higher temperature 

 than the atmosphere which surrounds the exhibitor. 



THAUMATROPE. 



