496 Mr. H. G. Wayling on Latent Heats of Fusion 



Then 



80xl0 _ 



273 ~ ^ Jt5 ' 



£. e. approximately equal to number of atoms in a molecule 

 of water. 



Twelve other examples are given to emphasize the relation- 

 ship. The data are taken from Landolt-Bornstein's Tabellen r 

 1912 edition. 



L x N Number 



Compound. ~ T ~' °. f at °7 



1 x in mol. 



Thallium Bromide, TIBr l^ZXl 1 ^ = 20 2 



733 



Calcium Chloride, OaOL .o4'6x54~ = 2-8 3 



1U47 



Lead Iodide. PbL n I^188 = 3.3 3 



Lead Chloride, PbCl 2 185 7 g ] 116 = 2'8 3 



Arsenic Bromide, AsBr 3 8 ' 93 3 ^ 138 = 4-0 4 



304 



•t cut, 9-76x156 . , . 

 Antimony Bromide, SbBr ;! -— — = 41 4 



Antimony Chloride, Sb01 3 H^*12? = 4-0 4 



Silver Chloride, AgCl 21 '^ 64 = 1*9 2 



Phosphorus Orychloride, POCl 3 19 ' 8 ^, 74 =5*3 5 



•i « -p 7-07x190 ,„ s _ 

 Stannic Bromide, SnBr 4 -- ■- - = 4 b & 



4Q-fi V n^ 



Sodium Chlorate, NaC10 3 528 = 4 ' 9 5 



Disodium Hydrogen Phosphate, 66-8 x190 _ A1 . n 44 



Na 2 HP0 4 12H 2 0. "309 - 



The last compound is rather exceptional among those con- 

 taining so-called water of crystallization, in that the molecules 

 of water appear to keep the value found in the uncombined 



state. 



When the majority of hydrated salts are studied, it is found 

 that the value of 2 for each molecule of water leads to re- 

 markably close approximation for the total number of atoms 

 in the molecule. Thus, allowing 2 for each molecule of 



