673 
We may further state that at the lowest three temperatures the 
vapour densities were not measured but calculated ; in view of the 
degree of accuracy desired this is quite permissible. The calculation 
was made by means of the above series in which, however, (©) is 
now no longer negligible. (To be continued). 
ERRATUM. 
In the Proceedings of the meeting of September 28, 1912. 
p. 415 1. 10 from the top: for 0.507834 read 0.057834. 
(November 28, 1912). 
