32 THE TONER LECTURES. 



uniformly in order that the iudividual shall exist iu good health. 

 Their centres must be well nourished and their supply of blopd 

 must be even and regular in order that their tone shall be well- 

 preserved. The initial lesion in cases of the kind considered in the 

 present connection may sometimes be a molecular or protoplasmic 

 alteration unrecognizable by our j^resent .means of research, or it 

 may be a vascular disturbance or lesion. 



Hypersemias and even minute hsemorrhages into the pons Varolii 

 and medulla oblongata doubtless sometimes occur after severe mental 

 work greatly prolonged under jiressure or excitement. Richardson^ 

 records the case of a well-known English statesman who had risen 

 to fame by working early and late. At last his acquired reputation 

 was at stake on a momentous question. AVhile speaking in the 

 great assembly of the nation he became faint, and was soon obliged 

 to i-etire. From that moment he was stricken with dialjetes, of 

 which he died. 



The cause of sudden disease in this instance, and the cause 

 of sudden death in others, ai-e to be looked for in extravasa- 

 tions, often minute, into vital regions of the medulla. In many 

 cases of sclerosis, paretic dementia, and epilepsy, I have examined 

 the medulla to discover the immediate cause of death, and have 

 always found recent congestive and ha^morrhagic areas in the floor 

 of the fourth ventricle. Widely dilated vessels are found contain- 

 ing freshly coagulated blood and surrounded sometimes by extrava- 

 sated blood. 



The most important conclusions to which our study has led may 

 be summarized as follows : 



1. Intellectual work does not of itself injure health or shorten 

 life, but mental over-work, particularly when associated with emo- 

 tional strain, is a frequent cause of nervous break-down and pre- 

 mature disease. 



2. The average longevity of men in the higher walks of public 



^ The Diseases of Modern Life. 



