Passage of Heat between Metal Surfaces and Liquids. 287 



Boiling point, 

 in degrees above 



Concentration, in 

 gram molecules 



CaCl 2 . . . . 



100°. 



. 0-048 



per litre. 



0-0293 

 0-0325 

 0-0485 

 0-0510 

 0-0530 

 0-0645 

 0-0880 

 0-1080 

 0-1240 

 0-0215 

 0-0400 

 0-0565 

 0-0680 

 0-0890 

 0-1105 



SrCl 2 . . . . 



0-054 

 0-073 

 0-079 

 0-085 

 0-102 

 0126 

 0155 

 0-169 

 0-035 

 0-059 

 0-083 

 0-097 

 0-122 

 0-145 



A full discussion must bo reserved till a later date, but here we 

 may notice that in all cases the numbers under the heading "Ratio" 

 will be found to be of the same order as those calculated from the 

 theory of Arrhenius (e.g., an electrolyte of type, R/Cl, when fully 

 dissociated, should give a ratio 1*04, and of type, R"C1 2 , 1*56). But 

 the discrepancy always exceeds the experimental error, except in the 

 case of potassium chloride, and is particularly great in the case of 

 calcium chloride. The latter substance gave less defined boiling 

 points than the others, for some unknown reason, and the experi- 

 mental error is here certainly at its greatest, but not nearly great 

 enough to account for the difference. 



Certain other deductions will be made from these results and others 

 which are accumulating, on a later occasion. My special thanks are 

 due to Mr. Griffiths, for much invaluable assistance, and to Professor 

 J. J. Thomson, for permission to use the Cavendish Laboratory. 



*' On the Passage of Heat between Metal Surfaces and Liquids 

 in contact with them." By T. E. Stanton, M.Sc. Com- 

 municated by Professor Osborne Reynolds, F.R.S. Re- 

 ceived April 7,— Read May 13, 1897. 



The determination of the rate of transmission of heat from the 

 surface of a heated metal to colder water in contact with it, or from 

 hot water to a colder metal surface, is a problem of some importance 



(Abstract.) 



