PROBLEMS OF INORGANIC CHEMISTRY. 33 



THE PRESENT PROBLEMS OF INORGANIC CHEMISTRY.* 



By Sir WILLIAM RAMSAY, K.C.B., F.R.S. 



^T^O discuss the ' present problems of inorganic chemistry ' is by no 

 -*- means an eas} r task. The expression might be taken to mean 

 an account of what is being actually done at present by those engaged 

 in inorganic research ; or it might be taken to relate to what needs 

 doing — to the direction in which research is required. To summarize 

 what is being done in an intelligible manner in the time at my dis- 

 posal would be an almost impossible task; hence I will choose the lat- 

 ter interpretation of the title of my address. Now, a considerable 

 experience in attempting to unveil the secrets of nature has convinced 

 me that a deliberate effort to discover some new law or fact seldom 

 succeeds. The investigator generally begins unmethodically, by ran- 

 dom and chance experiments; or perhaps he is guided by some indica- 

 tion which has struck his attention during some previous research; 

 and he is often the plaything of circumstances in his choice. Expe- 

 rience leads him to choose problems which most readily admit of solu- 

 tion, or which appear likely to lead to the most interesting results. 

 If I may be excused the egotism of referring to my own work, I may 

 illustrate what I mean by relating the following curious coincidence: 

 After Lord Rayleigh had announced his discovery that ' atmospheric 

 nitrogen ' was denser than ' chemical nitrogen/ I referred to Caven- 

 dish's celebrated paper on the combination of the nitrogen and the 

 oxygen of the air by means of electric sparks. Fortified by what I 

 read, and by the knowledge gained during the performance of lecture- 

 experiments that red-hot magnesium is a good and fairly rapid ab- 

 sorbent of nitrogen, it was not long before a considerable quantity of 

 nearly pure argon had been separated from atmospheric nitrogen. 

 Now it happened that I possess two copies of Cavendish's works; and 

 some months afterwards I consulted the other copy and found pen- 

 ciled on the margin the words ' look into this.' I remembered the 

 circumstance which led to the annotation. About ten years before, 

 one of my students had investigated the direct combination of nitro- 

 gen and hydrogen, and I had read Cavendish's memoir on that occa- 

 sion. I mention this fact to show that for some reason which I for- 

 get, a line of work was not followed up, which would have been at- 

 tended by most interesting results ; one does not always follow the clue 



* An address at the International Congress of Arts and Science, St. Louis, 

 September, 1904. 



vol. lxvi. — 3. 



