STRAIN AND OVER-ACTION OF THE HEART. 9 



I may mention irregularity or excess in eating and in drinking, 

 sexual disorders, long matrimonial engagements, the abuse of 

 tea, of coffee, of tobacco. There is, of course, a great deal to be 

 said about individual peculiarity favoring the development of the 

 complaint, and one person may do that or take that with impu- 

 nity which in another is sure to produce disturbance. Thus, 

 malt liquors alone give rise to irritability of the heart in one, 

 certain wines in another ; and in some families there runs a 

 strong tendency to palpitation, which is readily developed b}'' 

 causes influencing the heart that are without effect in others. 

 Of the sources of irritable heart alluded to, tobacco is one of 

 the most common. Its use not only produces irritability of the 

 organ, but immensely aggravates an existing tendency to 

 palpitation ; and one of the traits of the irritable heart due 

 to tobacco is that irregularit}'^ of the action, shown by inter- 

 mission or irregularity of beat, is a very ordinary feature. 



Yet another cause I may mention as giving rise to a per- 

 sistent excitement of the heart, and favoring its over-action, 

 are preceding febrile seizures, whether malarial or of continued 

 fevers. And cases thus originating may last for a veiy long 

 period. I saw recently one in a lady in whom the cardiac dis- 

 order began in a severe attack of typhoid fever twenty years 

 ago. But it is, perhaps, not fair to speak of these instances 

 as due to mere perverted action of the organ; there is often 

 a coexisting structural change in the muscle; for we find 

 in luany of these fevers by careful examination, certainly in 

 typhoid, in typhus, and in 3'ellow fever, a granular degenera- 

 tion of the muscular fibres of the organ. 



One of the most interesting circumstances connected with 

 the forms of over-action or over-excitement of the heart we 

 have been glancing at, is, that however purely functional this 

 shall have been at the outset, organic disease of the heart may 

 grow out of it. In the paper on the irritable heart of soldiers, 

 and previously in one forming part of the Medical Memoirs of 



