394 Intelligence and Miscellaneous Articles. 



results of our work. The liquid ammonia used in the experiments 

 was found on examination to contain 0*3 per cent, of moisture 

 and on spontaneous evaporation to leave only a trace of residue. 

 The impurities were therefore of no consequence in influencing the 

 result to the limit of accuracy intended. 



Of this liquid ammonia 10*01 grams were introduced into a 

 small steel cylinder of 16-122 c.c. capacity, stoppered by a steel 

 screw. The mode of filling was quite simple. After cooling the 

 cylinder in a bath of the liquid ammonia itself and while still 

 immersed, it was possible to pour it brimful by means of a beaker. 

 The steel screw stopper, also previously cooled, was then inserted 

 and drawn almost tight. On then removing the cylinder from the 

 cooling bath, the liquid contents gradually expanded and escaped 

 in quantity proportional thereto, and besides a very small vapour 

 space was allowed to form as is indicated in the experimental data. 

 Then the stopper was driven tight. Thus the error in the result 

 due to the latent heat of condensation of vapour of ammonia in the 

 course of the experiments was reduced to a minimum and 

 rendered, as will be seen, almost inappreciable in its influence. 



The cylinder was perfectly free from leakage and remained 

 constant in weight during each series of determinations. It was 

 suspended in the drum of a Eegnault apparatus heated by the 

 vapour of carbon disulphide. The entire mode of procedure was 

 in all details that commonly used in the Eegnault method. After 

 the cylinder had been heated for about six hours, it was dropped 

 into a brass calorimeter whose water value was 1*36 cal. and which 

 contained 150 grams of water. In each experiment it required 

 very nearly two minutes to raise the calorimeter to its maximum 

 temperature. The influence of loss by radiation was reduced 

 to a minimum by the Eumford manipulation. The thermometers 

 used were standardized, carefully compared, and read to hundredths 

 of a degree by means of a magnifying lens. The experiments were 

 conducted sufficiently far from the critical temperature, which 

 according to Vincent and Chappuis is 131° C. 



The following are the data of Experiment 1 : — 



Weight of steel cylinder and ammonia . .. 81-008 grams. 

 "Weight of steel cylinder 70-998 „ 



Weight of ammonia 10*01 „ 



The specific gravity of liquid ammonia being 0-656, the volume of 

 10*01 grams is 15-26 c.c. 



Total water value of calorimeter, thermometer, 



and water 151*76 cal. 



Water value of steel cylinder 8*34 cal. 



Temperature of air 25°*4 C. 



Temperature of steel cylinder 46°-51 C. 



Temperature of calorimeter after immersion 26°* 69 C. 

 Temperature of calorimeter before immersion 24°*44 C. 



Eise in temperature 2°*25 C. 



