Transition Layer between Two Adjacent Phases. 507 



The Surface-density of Water and its variation with 

 Temperature. ' 

 This has been measured . as m the previous case, by means 

 of equation (3). The temperature range is from U° to 100° C. 

 The value of "a" is due to #i,n jer.'WaaU.*, namely, 3*467 

 (units : gram molecule, atmosphere, -litre). When.we take 

 the gram as unit thi.-s number becomes 0*0107. . ii is,-regarded 

 as constant throughout the range of temperature, which is 

 approximately correct as iong -a=> we -are sufficiently far 

 distant from the critical temperature. (The value for a 

 found for 100° C. is 0'0105 on the same units, cf. foregoing 



Table II. — Water : Surface density. 



Temperature 



°C. 



Bulk density, 

 gram/c.c. 



3-61 

 13-95 

 25-14 

 3731 

 50-64 

 65-36 

 81-71 

 100-0 



1-0000 

 0-9993 

 09971 

 09935 

 0-9880 

 0-9807 

 0-9707 

 0-9587 



Bulk 

 Specific 

 Volume, 



v —L 



10000 

 1-0007 

 10029 

 10066 

 10120 

 1-0196 

 10302 

 10431 



Latent heat, 

 cals. per gram 



588-4 



584-74 



58013 



574-35 



567-26 



558-62 



548-19 



535-78 



==- (when 

 M 



M=18). 



(cals.) 



30-78 

 31-89 

 3311 

 34-45 

 35-99 

 3756 

 39-45 

 41-45 



Temperature 

 0°C. 



in cals. 



361 



557-6 



13-95 



552-9 



2514 



5470 



37 31 



5399 



50-64 



531-3 



65-36 



521-1 



81-71 



508-7 



1000 



4943 



in litre 

 atmospheres. 



in c.c. 



* s 

 gram/c.c. 



23-42 

 2321 

 2297 

 22-68 

 22-31 

 21-89 

 2136 

 20-76 



0-4568 

 04610 

 0-4658 

 0-4719 

 0-4796 

 0-4888 

 0-5009 

 05153 



2-189 

 2-169 

 2-147 

 2119 

 2-084 

 2-046 

 1-996 

 1-940 



2-189 

 2-171 

 2153 

 2133 

 2-109 

 2-086 

 2056 

 2023 



* This value of " a " gives K m 

 {Continuitat" etc.) 



10700 atmospheres at 0° C. 



