12 PROPERTIES OF STEAM AND OTlli K VAPORS. 



For the Fahrenheit scale the equation becomes 



// - 1091.7 -I- 0.305 (/ - 32). 



An investigation of the original experimental result>, allowing for the 

 tnie specific heat of the water in the calorimeter. >howed that the probable 

 errors of the method of determining the total heat were larger than the 

 lions of the true specific heats from unity, the value- assumed by 

 Regnault; and, further, it appeared that his equation n our IK st 



knowledge of the total heat of steam. There appears to be no reason for 

 changing this equation till new experimental values shall be supplied. 

 The deviation of individual experimental results from corresponding 

 computations by the equation is likely to be one in five hundred. There- 

 is further some uncertainty whether the method of drawing steam from 

 the boiler did not involve some error due to entrained moisture. The 

 best check upon Regnault's results is a comparison with Knoblauch's 

 work on superheated steam. 



The total heats for various fluids are given by the following equations: 



Ether H = 94 -f o.45/ O.OOO55556/ 2 



Chloroform .... H = 67 +'o.i375/ 



Carbon bisulphide . . H == 90 4- o.i46oi/ 0.0004123^ 



Carbon tetrachloride . H == 52 + 0.14625* - 0.000172? 



Aceton H = 140.5 4- O.36644/ 0.000516^ 



Specific Volume of Liquids. The coefficient of expansion of most 

 liquids is large as compared with that of solids, but it is small as compared 

 with that of gases or vapors. Again, the specific volume of a vapor is 

 large compared with that of the liquid from which it is formed. Con- 

 sequently the error of neglecting the increase of volume of a liquid with 

 the rise of temperature is small in equations relating to the thermo- 

 dynamics of a saturated vapor, or of a mixture of a liquid and its 

 vapor when a considerable part by weight of the mixture is vapor. It is, 

 therefore, customary to consider the specific volume of a liquid to be 

 constant. 



Table XII, giving the specific volumes of various liquids, was taken 

 from the Phys.-Chem. Tabellen of Landolt and Bornstein. 



Volume of Water. Table XIII gives the volumes of water compared 

 with its volume at 4. From o to 100 C., the values are those given by 



