EXPERIMENT STATION BULLETINS. 



663 



which complete fusion took place and the temperature passed the 32° F. 

 point was proportional to the concentration of the treatment. It will 

 be noticed that by the time the temperature of the sand treated ^v1th 

 water began to rise above 32° F., the degree of magnitude of the tem- 

 perature of the other lots of sand varied directly with the density of the 

 solution. In the case of the KCl experiment for instance, the differ- 

 ence in temperature between the sand treated with water and that 

 treated with 1.5 normal solution was as great as 17° F. Finally, how- 

 ever, all the differently treated sands attained about the same tempera- 

 ture. The differences noted increase with the decrease in concentration 

 of the solution and would necessarily exist on account of the difference 

 in evaporation. 



Experiment 2, This experiment was an extension and check to the 

 foregoing experiment. It consisted in studying the effect of 0.0, 0.5, 1.0 

 and 1.5 normal solutions of NaCl and KCl and 1.0 normal solutions of 

 K2CO3, NaNOa, CaCL KNO3, and (NHJ0CO3 upon the rate of freezing, 

 the degree of the lowering of the freezing point, and the rate of the 

 rising of temperature. It was prepared by placing 6855 grams of quartz 

 sand in the regular wooden boxes, added 750 cc of the respective solu- 

 tions, and the temperature records were taken in the usual manner. In 

 the table below is given only the lowering of the freezing point, the 

 rate of freezing and of thawing are left out on account of lack of space; 

 the general trend of these, however, is well illustrated in the foregoing- 

 experiment. 



TABLE 89.— FREEZING POINT OF SOLUTIONS IN SAND. 



Name of solution. 



Freezing 

 point. 



Water 



0.5 N. NaCl 



1.0 N. NaCl 



1.5 N. NaCl 



0.5 N. KCl 



1.0 N. KCl 



1.5 N. KCl 



l.ON. K2CO3 



l.ON. KNO3 



l.ON. CaCl2 



1.0N.(NH4) 2CO3 



31.8 



28.8 



25.4 



22.2 



29.0 



25.6 



23.0 



28. 



26. 



27. 



28.2 



It will be seen that the low^ering of the freezing increased with the 

 concentration and that it varied but slightly among the different salt 



solutions of the same strength. 



