TOTAL AND SPECIFIC HEAT 187 



one calorie will raise one gram 424.5 meters. The terms kilo- 

 calorie, or kilogramdegree, and kilogrammeter are used some- 

 times, and represent 1,000 times the calorie and grammeter 

 respectively. 



Total and Specific Heat. The temperature of a body indi- 

 cates nothing as to the quantity of the heat it contains. The 

 degree of heat requires only a thermometer to determine it, but 

 the quantity depends on the temperature, the weight and the 

 specific heat of the substance in question. 



Specific heat is analogous to specific gravity. Water is taken as 

 the standard in both cases. If it require only .5 calorie to raise 

 i gram of a certain substance i degree C., the specific heat of that 

 substance is said to be .5. The specific heat of the body is .8; 

 that is, whereas it requires a certain amounnt of heat to raise 

 150 pounds of water to a certain temperature, it would require 

 only .8 as much to raise a human body weighing the same to 

 the same temperature. To find the total heat in calories in any 

 body it is only necessary to multiply the weight (in grams) by 

 the specific heat and by the temperature C. Estimates made 

 by calorimetry from these data and from the potential value of 

 the different foods give the total daily heat production as about 

 2,500,000 calories for the average individual. This is equal to 

 about 1,400 calories per hour per kilo weight. 



The English heat unit is the pound-degree F. It is the amount 

 of heat necessary to raise i pound of water i degree F. Its 

 mechanical equivalent is the force necessary to raise i pound 

 772 feet. The estimates just given in the metric system when 

 translated to English nomenclature give the total heat produc- 

 tion for 24 hours as about 8,400 pound-degrees, or 2.5 per hour 

 per pound weight. These figures are given as only approx- 

 imate and are subject to change by many causes, such as sex, 

 cardiac and respiratory activity, internal and external temper- 

 ature, exercise, digestion, age, nervous influences, the body 

 weight, etc. 



