80 THE POPULAR SCIENCE MONTHLY. 



that accompanies the tobacco-habit also sustains this hypothesis ; and 

 this may be produced in animals by introducing a very minute dose 

 of decoction of tobacco into the system by way of the niouth, while 

 subcutaneous injection is not equally rapid in producing this special 

 result, nor, indeed, in producing death. Nor have I any doubt, from 

 the few experiments I have tried, and the many I have witnessed, that, 

 in opium-smoking, the peculiar symptoms are occasioned by a similar 

 action of the vapor of the drug (on the medullary tract by way of the 

 pneumogastric nerves). The olfactory nerves are, of course, more or 

 less affected, and transmit the specific influence of either drug directly 

 to the interior lobes of the brain ; but experiment and observation 

 alike tend to the conclusion that, though dizziness is somewhat accel- 

 erated by this action, it is trifling even in its cerebral effect, and that 

 the great thoroughfare of activity is by way of the pneumogastric. 

 The disturbances in locomotion arising from tobacco are thus sec- 

 ondary effects propagated, not by way of general nervous disturbance, 

 but by direct appeal to the great coordinating centre, the cerebellum, 

 through the near-lying and directly-connected vital tract. The ver- 

 tiginous symptoms that accompany disturbances of the latter class 

 must not be confounded with those that originate by way of the olfac- 

 tory nerves, as the whirling sensation is far more marked and distinct 

 in cerebellar disturbances, while the tendency to unconsciousness is 

 somewhat less so. 



I am, in these remarks, let it be understood, simply giving the 

 results of my own observations on my own person during the last 

 thirteen years ; and my conclusion, from the masses of data thus ac- 

 cumulated, is, that the great sensory and motor tract of gray neurine, 

 known as the cortex, is not at all involved in the primary stages of the 

 narcotism induced by smoking, though the reverse is often clearly true 

 in the instance of opium, with its surer and swifter cerebral effect. 

 Others may be very differently affected by habitual smoking. I sim- 

 ply contribute my leaf to the record ; and, although I am not satisfied 

 that the tobacco-habit ever produces neurosis, I am satisfied that it is 

 often the exciting cause of nervous disorder in cases where the neu- 

 rotic tendency exists, and that in these cases it is productive some- 

 times of morbid moral phenomena, in a degree only less marked than 

 the epileptic aura, and penetrating to the very roots of volition and 

 ethical emotion. My opportunities for observation in hospitals and 

 asylums have not been extensive enough to permit me to pronounce 

 definitely on the point I am about to suggest ; but it is my impression 

 that the larvated type of epilepsy occurs more frequently than any 

 other among persons addicted to tobacco, and that the habit is very 

 generally influential in the larvation of nervous maladies. Statistics 

 only can settle this issue, which must be left to the consideration of 

 medical psychologists. 



In order that the lay reader may clearly apprehend the various 



