12 THE TONER LECTURES. 



of irritable heart and functional disorder, in connection with 

 cerebral, or spinal, or gastric maladies, may be explained. 

 But I incline to accord to disturbance of the s^^mpathetic ele- 

 ments of the cardiac plexus. the chief part in leading to the mani- 

 festations of distress. Moderate irritation, Moleschott proves 

 stimulates their action-,, and this irritation may originate in 

 them, but is much more likely reflected to them, as from the 

 great abdominal sympathetic ganglia; 4ind thus you have the 

 probable explanation of the functionally disturbed heart of 

 gastric and of uterine affections. Further, from the perverted 

 innervation comes altered nutrition, and thus heart disease 

 may grow out of heart disorder; as we now know that struc- 

 tural alteration of the skin, or of the joints and other parts 

 of the economy, may result from abnormal nerve influence. 

 xSay, in the light Of these remarks, we can understand how 

 even mental emotion, acting through the nervous system on 

 the nerves of the heart, may produce real trouble, and how the 

 worry of life, and strain on the feelings, when long kept up, 

 may give rise to conditions which, in figurative language, we 

 ca "heart-weary," and "heart-sick," and which, not as a 

 figure of speech, but in truth, may be the beginning of 

 actual cardiac malady. 



But it would lead me too far to pursue this matter here any 

 furtlier. I merely looked at it incidentally in trying to make 

 clear tliat excitement and over-work of the heart first disorder 

 the function, and then may produce organic change, and in 

 attempting to explain how this happens; and shall call your 

 attention to a subject of great and wide interest which has the 

 closest connection with what we have been discussing — the 

 eff'ect of certain occupations, nay, of our amusements, in lead- 

 ing to cardiac trouble from the constant strain and over-work 

 thrown on the heart, partly in the gradual manner just de- 

 scribed, through perverted nervous action — but partly, also, 

 by directly causing inflammatory and other tissue change. 



