VERTEBRATED ANIMALS. 79 



attention, and several philosophers made experiments 

 on their own persons with a view of testing and 

 explaining such a singular phenomenon. Of these 

 experiments, probably the most accurate and decisive, 

 and certainly the most famous, were those of Sir Charles 

 Blagden and Dr. Fordyce. The room where these cele- 

 brated experiments were made was heated by flues, 

 there being neither chimney nor any other aperture 

 where the heat might escape. 



In the first experiment, Sir Charles went in, with 

 wooden shoes on his feet, the heat being a little above 

 that of boiling water. The first impression is described 

 as exceedingly disagreeable, but in a few minutes all this 

 uneasiness was removed by the breaking forth of a pro- 

 fuse perspiration. Having staid twelve minutes, he 

 came out with a sense of fatigue, but nothing more, the 

 thermometer then standing at 220. 



It was afterwards found that the temperature of 260 

 could be endured for a short time, without much diffi- 

 culty. But the most curious part of these experiments 

 were the sensations produced by touching their own 

 persons on some vital part, or touching each other, and 

 also objects in the room. Every piece of metal about 

 their persons, as their watch chains, became intolerably 

 hot ; small quantities of water placed in metallic vessels, 

 boiled in a few minutes. Though the air of the room 

 was 260o, it could be taken into the lungs with impunity, 

 but the boiling water in which the thermometer indica- 

 ted only 212, scalded the finger as usual. Eggs and 

 beef-steak suspended in wire nets, were completely 

 done in from five to fifteen minutes, and still the gentle- 

 men were able to remain in the room. But notwith- 

 standing dead matter became heated to the temperature 

 of the air, as was expected, the persons of the gentle- 

 men never rose higher than about 101, or at most 102, 

 as indicated by the thermometer, with the bulb placed 

 on the tongue, or under the arm. 



The hands being at a distance from the vital parts, 

 were heated to a much higher degree, so that when the 



What were the degrees of heat to which Sir C. Blagden and Dr. For- 

 dyce exposed themselves ? 



