AND SCHONBEIN 71 



potassium ozonide. The sulphuric acid separates the 

 iodic acid from the potash, and part of the oxygen of 

 the latter acid combines with the potassium of the 

 ozonide, setting free iodine and ozone." This single 

 passage is, I think, sufficient to place the point in 

 question in the right light. It was not because I 

 had not thought of the method that I did not treat 

 my salt with chlorine. But I only had, so to speak, 

 homoeopathic quantities of the salt, and so I could 

 only perform a few incomplete experiments with it ; 

 and as I wished to see whether I could obtain from 

 it a body similar in its reactions to chlorine or ozone, 

 I intentionally abstained from employing the former. 

 Originally I mixed my salt with pure manganese 

 dioxide, and then on treating it with sulphuric acid 

 I obtained the reactions I have described; but I 

 found out later that the manganese dioxide was 

 quite unnecessary, and that the reaction was due to 

 the presence of potassium iodate. The fact that a 

 solution of the salt, when treated with any acid 

 colours starch paste containing potassium iodide blue, 

 likewise makes the presence of potassium iodate con- 

 ceivable. However, I do not attach any importance 

 to these preliminary experiments, since they were 

 performed, as I have said, with such small 

 quantities. 



You are quite right in saying that the plan which 

 I have adopted of using potassium iodide to absorb 

 the ozone, liberated by means of phosphorus, is very 

 laborious, but I am bound to say that up to the 

 present moment I know of no better. Mercury, for 



