RICHARDS AND ROWE. — THE SPECIFIC HEATS OF LIQUIDS. 487 



The Heat of Dilution of Sodic Hydroxide NaOH • 5.85 HoO. 



The variation from the mean falls within the probable experimental 

 error (0.001°). 



Obviously any thermochemical effect produced by the mixing of two 

 liquids could be measured in the same way. It is to be noted that 

 the method has a great advantage over other methods in that great 

 speed in the execution of the experiment is not at all necessary. By 

 the old methods, speed was essential because of the correction for 

 cooling ; but here there is no correction for cooling because the per- 

 formance is strictly adiabatic. The reaction may extend over hours, 

 if necessary. 



It should be noted that the correction concerning the sodic hy- 

 droxide could be wholly avoided if the pure alkaline liquid were con- 

 tained in a receptacle within the calorimeter, instead of being held in 

 a burette above it. Such a receptacle has been used successfully by 

 Richards and Henderson ^^ and was not introduced in these prelimi- 

 nary experiments on account of its slightly greater complexity. In 

 the future it will be adopted, and with it we hope to secure yet more 

 accurate results. 



Experiments are now under way for the determination of the specific 

 heats and heats of dilution of various solutions at different concentra- 

 tions and at different temperatures, by the methods just described. 



It is a pleasure to acknowledge the generous aid of the Carnegie 

 Institution of Washington, without which we should have been greatly 

 hampered in this work. The present and future results of this investi- 

 gation will be published in greater detail by that Institution, in one of 

 its shortly forthcoming regular publications. 



2* These Proceedings 41, 11 (1905) ; Zeit. phys. Chem., 52, 551 (1<J05). 



