34 ESSAYS BIOGRAPHICAL AND CHEMICAL 



Solitary he lived, and solitary was his death. Having 

 been ill for several days, his valet was called to his bed- 

 side, and told to summon Lord George Cavendish, as soon 

 as he should be dead. In about half an hour he again 

 summoned the servant, and made him repeat the 

 message. He then said, ' Right. Give me the lavender 

 water. Go.' Half an hour later the servant returned to 

 his room, and found that he had expired. 



If Boyle found interest in all things human, Cavendish 

 appeared to take no thought of anything, except 

 phenomena. As his biographer, Dr. George Wilson, said, 

 his motto was Panta metro, kai arithmo, kai stathmo 

 (Tlavra /jLerpy, Kai apiO/jbw, Kai araOfjiq)). This we shall 

 now learn, from a short consideration of his work. 



Cavendish's earlier work is only to be found in his un- 

 published papers. It appeared to have been his habit, 

 for some time, to write an account of his experiments, 

 without any intention of bringing them to the notice of 

 the public. An account of two long investigations was 

 found among his papers, after his death, of a date con- 

 siderably prior to that on which his first memoir 

 appeared in the Philosophical Transactions. The first 

 of these deals with the differences between 'regulus of 

 arsenic' (metallic arsenic) and its two oxides. He con- 

 cluded that arsenic oxide was ' more thoroughly deprived 

 of its phlogiston ' (in modern language, more thoroughly 

 oxidised) than arsenious oxide; and the latter, than 

 arsenic itself. The paper also contains speculations on 

 the nature of the red fumes obtained in the conversion 

 of arsenious to arsenic oxide by means of nitric acid ; 

 speculations which were afterwards to bear rich fruit, in 

 his work on the composition of air. 



Another of his unpublished researches deals with heat. 

 Cavendish discovered independently the laws of specific 

 heat ; and he collected tables of the specific heats of many 



