EXCESSIVE EXERCISE OF THE BRAIN. 231 



Some very marked cases of this kind have come 

 tinder my observation, but that of Sir Humphry 

 Davy is so strikingly illustrative of the dangers al- 

 luded to, that 1 cannot do better than lay it before 

 the reader. In November, 1807, Sir Humphry Davy 

 was seized with very severe fever, in consequence 

 of the excitement and fatigue which he underwent 

 when engaged in his splendid discovery of the alka- 

 line metals. " The laboratory of the institution was 

 crowded with persons of every rank and description ; 

 and Davy, as may be readily supposed, was kept in 

 a continued state of excitement throughout the day. 

 This circumstance, co-operating with the effects of 

 the fatigue he had previously undergone, produced 

 a most severe fit of illness, which, for a time, caused 

 an awful pause in his researches, broke the thread 

 of his pursuits, and turned his reflections into dif- 

 ferent channels." Davy ascribed his illness to con- 

 tagion caught in experimenting on the fumigation 

 of hospitals. " Upon conversing, however, with Dr. 

 Babington, who, with Dr. Frank, attended Davy 

 throughout this illness, he assured me that there 

 was not the slightest ground for this opinion, and 

 that the fever was evidently the effect of fatigue and 

 an over-excited brain. The reader will not feel much 

 hesitation in believing this statement, when he is 

 made acquainted with the habits of Davy at this 

 period. His intellectual exertions were of the most in- 

 jurious kind, and yet, unlike the philosophers of old, 

 he sought not to fortify himself by habits of tem- 

 perance." " Such was his great celebrity at this 

 period of his career, that persons of the highest rank 

 contended for the honour of his company at dinner, 

 and he did not possess sufficient resolution to resist 

 the gratification thus afforded, although it generally 

 happened that his pursuits in the laboratory were no* 

 suspended until the appointed dinner hour had passed 

 On his return in the evening, he resumed his chymica. 

 labours^ and commonly continued them till three or four 



