UQUIDS AND ALI.IED EXPERIMENTS. 



As a whole, these experiments show the absokite necessity of long inter- 

 vals of observation. Whether it be a gradual decline in temperature or 

 solutional effects, or whether fresh solutions or even water require a long 



Table 21. 



time-interval to reach rigorously normal conditions of equilibrium, the 

 result is patent that the true diffusion rates do not appear until the time- 

 interval has been prolonged sometimes as much as live or six weeks. Even 



5-2. 

 50 



4-8 1 



Oct^e 3lcMn).^ _iO 15 20 25 30 



Fig. 20. — Chart showing loss of standard 

 volumes of gas in diver in lap.se of 

 days. Diffusion of air through water. 



if the curve is smooth, it is always hazardous to assume that the true diffu- 

 sion rate has been exhibited within a month. 



The double-tube apparatus // charged with fresh water and air showed 

 the dift'usions contained in table 22 and fig. 20. 



