Table 239. 



EFFECT OF COMPOSITION ON THERMOMETER ZERO. 



Jena Glasses. 



Table 240. 



CHANCE OF ZERO OF THERMOMETER WITH TIME. 



Closely allied to the changes illustrated in Tables 235-237 >s the slow change of volume of the bulb of a thermometer 

 with age. The following short table shows the change for the normal Jena therraometer.J; 



Smithsonian Tables. 



* Fresenius, " Zeits. fur Anal. Chem." vol. 27, p. 189. 



t Normal Jena glass. 



X AUihn, " Zeits. fur Anal. Chem." vol. 29, p. iSs- 



231 



