Human Physiology. 



organs, lessen the power to resist morbific agencies, and so 

 leave the system a prey to other diseasing influences and con- 

 ditions. The intemperate, and those whose vital powers have 

 been lowered by the use of stimulants, are the first and most 

 numerous victims of many epidemic diseases, and are especi- 

 ally liable to fevers and several forms of local* disease. The 

 difference between the action of alcohol and other narcotics in 

 common use, such as opium, tobacco, coffee, tea, &c. is not, 

 in all respects, unfavourable to alcohol, which, in small quanti- 

 ties, passes more ^rapidly out of the system than the others, 

 and, strength for strength, makes a less injurious impression on 

 the nervous system. It is, however, a point in favour of. the 

 others that they do not so readily produce mania, or violent 

 and debasing excitement. Opium, however, in a quieter way, 

 seems as demoralising as alcohol ', and tobacco, I am satisfied, 

 has a stupefying effect upon the higher moral faculties. Tea 

 and coffee, which are said to " cheer but not inebriate," have 

 a very bad influence upon the nervous systems of many per- 

 sons, and are the undoubted causes of a great deal of nervous 

 disease. One of the principal causes of the breaking-down, 

 nervous exhaustion, brain softening, and heart disease of men of 

 great intellectual activity, is their working upon stimulants, 

 chiefly tea, coffee, and tobacco. If they worked simply upon 

 their own unstimulated strength, and stopped when they were 

 tired, they would rest and recover; but when the normal ner. 

 vous power, the natural capacity for work, is exhausted, they 

 stimulate, spur up their brains to more effort, and it is this 

 extra effort which exhausts them and brings on apoplexy, 

 paralysis, &c. And it must be remembered that whatever 

 exhausts, directly or indirectly, the nervous power the vital 

 force that is manifest in the nervous system of organic life 

 must be a cause of disease. The man who does physical or 

 mental work upon the stimulation of alcoholic drinks, or the 

 finer and more subtle stimulation of other narcotics, sooner or 



