Prof. H. KAMERLINGH ONNES and Dr. W. H. XEESOM. On the equation of state of a substance in the 

 neigbourhood of the critical point liquid-gas. II. Spectrophotometrical investigation of the opal- 

 escence of a substance in the neigbourhood of the critical state. 



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CI 



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Fig. 1. 



It. "■'< IK lu )«. ij.fc no. m. I3.S. 



Fig. 2- 



Proceedings Royal Acad. Amslerdarn. Vol. X. 



