n8 Prof. Dixon and Mr. Harker on the 



On the combination of Hydrogen and Chlorine, alone, 

 and in presence of other gases. By Harold B. 

 Dixon, M.A., F.R.S., Professor of Chemistry, and 

 J. A. Harker, Research-Student in the Owens 

 College. 



{Received December 2Jth, 1889.) 



Is the combination of hydrogen and chlorine affected 

 by the presence or absence of moisture ? Does hydrogen, 

 when exploded with an excess both of chlorine and of 

 oxygen, unite entirely with the chlorine or divide itself 

 between the two ? 



The evidence on the first point is conflicting ; on the 

 second we have the definite statement of C. Botsch {Annalen 

 210, p. 207) that the hydrogen does not divide itself between 

 the chlorine and oxygen, but goes entirely to the chlorine. 

 Botsch's experiments, however, are not accurate enough to 

 make us feel sure of his conclusion, which he admits is 

 a priori improbable. 



In a communication made to the Chemical Section of 

 the British Association at Newcastle last September, we 

 brought forward some evidence bearing on these questions. 

 Our object was to work out the law according to which 

 hydrogen divides itself between chlorine and oxygen in an 

 explosion of the three gases. It was first necessary to 

 determine whether direct union between dry hydrogen and 

 chlorine takes place under the conditions of our experi- 

 ments. We found that sparks from an induction coil, passed 

 through the gases between wires of platinum-iridium, caused 

 the instantaneous explosion of the mixture after it had been 

 standing for days in contact with anhydrous phosphoric 

 acid. Combination between dry hydrogen and chlorine is 



