CANE SUGAR. 



143 



solution. Otherwise, much time is lost in waiting for equilibrium, and 

 some dilution occurs in consequence of the compression of the gas in 

 the manometer. Up to the present time, however, the writer has been 

 unable to devise a successful means for producing this initial pressure 

 which did not involve the use of rubber. 



Throughout Series VII and VIII, the temperatures of the bath were 

 constant, and with the introduction into the latter of the new device 

 for closing the cells, the last traces of loss in rotation disappeared. 

 With Series VIII, therefore, the four years' struggle against thermometer 

 effects and dilution was brought to a successful issue. 



The progress of the work from the beginning to the end of the 

 endeavor to eliminate the large sources of error from the direct method 

 of measuring osmotic pressure is summarized, and can be reviewed at a 

 glance in Tables 34, 35, and 36. 



Table 34. — Cane sugar, Series I to VIII. Fluctuations in bath temperature. 



Table 34 gives the fluctuations in bath temperature for each of the 

 175 experiments of Series I to VIII, inclusive. The test and the 

 measure of progress in the improvement of the facilities for the main- 



