On The Power Of The Human Body To Resist Heat

It was long believed that the human body could not be safely exposed, even for a short time, to a degree of heat much exceeding that which is met wilh in hot climates. This opinión, which we know now to be erroneous, was strengthened by the result of eome experiments made by the celebrnted Fahrenheit himself, nnd related by Boerlmve. Some animáis were shut iip n a sugar btiker's stove, wliere the merctiry stood at 136 degrees. A sparrow dietl in Ies6 than seven minutes, o cit in rothei more than a qnarter of an honr, and a dog in abone twenty-eight minutes. - The noxious air of the stove had probably more t o do with the speedy death of these animáis than 'he heat. The truth upon this biibjecl may be said to have been di?covered by accident. In the years 17G0 and 1761, M. M. Dnhnmel and .Tillet were appointeí to devise some means of óestroying an insect which coneunied the grain in the province of Augoumais, in France. They found that this could be done by snbjecting the corn. and insect contained in it, in an oven, to a degree of heat great enough to kill the insect,but not so gieat as to hurt the grain. In order to ascertain the precise heat of the oven, they intoduced into it the tli3rnr-met er, placed upon the end of a long shovel. The mercury, when the thermometer was withdrawn, was found to indícate a degree of beat considerably above boillng water. But I Mr. Jillet was aware that the thermometei had sunk several degrees as it was drawn toword the mouth ofthe oven. While he was puzzled lo invent some wny of determining more exactly the degree cf heat, a girl, who was one of the attendants, offèred to go in and mark with a peneil the heat at which the mercury stood; and she did enter the oven, and remained there two or three minutes, am themnaiked the thermo.neter at 100 degrees of Reaurnar, which nearly equals260 degrees of Fahrenheit. M. Jillet then began to express pome anxiety for the safety of the girl, bui . :e assured him she feit no inconvenieuce, nnd lemained in the oven ten minutes longer, during which time the mercury reached the 283 degrees of Fahrenheit s scale - denoting 7G dogrees of heat above that of water when it boils. When sho carne out her color was considerably heightened, but her respiration was by no means quick or laborious. Thie experiment was afterwads repeated. Anoth er firl remained in the oven as long as the former had done, at the same temperature,nnc with the eame impnnity. Nay, she even bronthod, for the space of five minutes, air heated to about 325 degrees of Fahrenlieit - or 113 degrees above that of boiling water. The publication of these facts naturally excited the curiosity of scientific men, nnd olher experiments were soon instiuied. Dr. Dob son of Liverpool, and several other persons with him, fluit ihemselves up in the sweating room of the hospital there - the air hoving been heated till the meicury stood at 224 degrees of Fahrenheit. They did not experience any oppressivè or painful sensations ol heat. Dr. Fordyce and Dr. Blagden made some remarkable trials of the same kind. - They entered rooms artih'cially heated to a very high degree - sometimes naked and aome times with their clothes on, and bore tbe extraordinary temperature of L40 and even L60 degrees for a considerable time, with very little inconvenienco. In all these experiments it was found that the anima] heat, as ascertained by thermometers placed iinder the longue, org'asped in the tand, was scarcely increased nt all, and the respiration but liltle affected: but the pulse was very much quickened. The freqnency of Dr. Blbgdeii's pulse in one instance was doubled. Their watch chainsand other pieces of mcal about them, became so hot that they could ecarcely be touched. When they )reathed upon the thermometerp, the mercury mmediaiely sunk seve"ul degrees. Eitch act of respiration produced a pleasant feeling of coolness in tiie nostrile, and they cooled their ingors by breathing upon them. ín and by he same heated air which they respired, eggs veré roistcd quito hard in twenty minutes, and beef steaks were dressed in thirty-thiee ninutfis. And when the air was blown upon he ment by means of bellows, it was suíBcient y-cooked in thirteen minutps.