168 FOODS 



from man by Parkes and Wollowicz, and many since they worked, show 

 an increased suddenness of ventricular systole and a shortening of the 

 pause between the systoles. Zimmerberg showed that large doses depress 

 both the rate and the power of the beat. Whether blood-pressure be 

 increased or not depends in any case on the balance between the aug- 

 mentation of the pumping-action by the heart and the size of the arterioles 

 and capillaries through which the streams must pass. Sometimes, 

 therefore, the pressure will be increased, sometimes decreased, sometimes, 

 doubtless, ' unchanged by the ingestion of moderate doses of alcohol. 

 Alcohol's harm on the heart is brought about partly, it appears, by the 

 shortening of the rest-period which it produces, as mentioned above, for 

 this soon leads to hypertrophy and general derangement, since no 

 portion of an organism can work continuously. 



Such are the chief of the physiological effects of alcohol on the animal 

 economy as now understood by physiologists. They go to show to the 

 student of medicine that alcohol may be of great use as a therapeutic 

 agent in disease, feeding the body, sustaining the mind, improving 

 digestion, supporting the heart when perhaps all that is necessary for 

 saving a life is this feeding, sustaining, improving, or supporting for a 

 brief period of time. But these physiological effects go to show to all 

 men that alcohol, although a sedative, is an irritant and depressive poison 

 generally inimical to life, with which a normal individual should have, 

 even physiologically speaking, nothing to do. 



Tobacco is so frequently practically a part of a meal, that it is not 

 improper to consider its effects briefly in this place. The active principle 

 of tobacco is an alkaloid nicotine, with the empirical formula C 10 H 14 N 2 . 

 Pictet and Rotschy claim to have discovered in tobacco three other 

 alkaloids: "nicotimin," with composition like nicotine's; "nicotem," 

 (C 10 H 12 N 2 ); and "nicotellin," (C 10 H 18 N 2 ). They find in ten kilos of 

 tobacco-juice 1000 grams of nicotine, 20 grams of "nicotein," 5 grams 

 of "nicotimin/' and 1 gram of " nicotellin," and announce the action of 

 the nicotei'n to be like that of nicotine, but more toxic. We shall look 

 at the action of nicotine on the nervous system, on the mind, and on the 

 circulation. 



On the nervous system the action of nicotine is complicated. It has 

 the peculiar power certainly of so disturbing the neurones as to block 

 the afferent impulses leaving them. It also paralyzes the peripheral 

 motor nerve-endings after a brief preliminary excitation of them. The 

 convulsions which follow large doses of the alkaloid have been shown 

 by Krocker to be quite independent of the brain, to be occasioned, then, 

 in the cord. Sensory centers and nerves are not affected by nicotine. 

 In what manner it affects the nervous system so as to abolish the general 

 sensation and pain of hunger, one of its conspicuous effects, it is impossible 

 at present to say, possibly by its peculiar sedative action, as in case of 

 opium. 



On the mind nicotine exerts a strong calming and quieting effect, while 

 at the same time the brain is so stimulated that long-continued mental 



