3dO 



LATENT AND SPECIFIC HEAT. 



heat units gained by that quantity of water for each degree of 

 change of temperature. Then will 9 represent the number of heat 

 units gained by the water in passing from to 9. But no heat 

 has been destroyed or wasted ; what the mercury has lost, the water 

 has gained. 



Mercury. Water. 



Specific heat x 1 



Weights taken 3 1 



No. of degrees of change 91 9 



Heat units .273z = 9 



/. x = .033, the specific heat of mercury. 



534. Heated Balls Melting Wax. The differ- 

 ence between bodies in respect to specific heat may be 

 roughly illustrated as follows : small balls of equal weight, 

 made severally of iron, copper, tin, lead and bismuth are 

 heated to a temperature of 180 or 200 C. by immersing 

 them in hot oil until they all acquire the temperature of 

 the oil. They are then placed on a cake of beeswax about 



half an inch 

 thick. The iron 

 and copper will 

 melt their way 

 through the 

 wax, the tin will 

 nearly do so, 



while the lead 

 FIG. 257. -II- . i_ 



and bismuth 



sink not more than half way through the wax. 



535. Reference Tables. (1.) Specific Heat of some sub- 

 stances : 



Iron 1138 



Copper 0952 



Silver 0570 



Tin 0562 



Mercury 0333 



Lead.. ....... .0314 



Hydrogen 3.4090 



Water 1.0000 



Ajnmonia (gas) 5084 



Air 2375 



Oxygen 2175 



Sulphur 2026 



Diamond 1469 



Bismuth 0308 



