308 THE EVOLUTION AGAINST NARCOTICS 



his power of resisting tuberculosis nor greatly increases his power 

 of tolerating alcohol. That is, he cannot acquire immunity to 

 the former nor learn to take, without intoxication, doses of the 

 latter, a waste product (the chemical composition of which is 

 much less complex than that of the toxins) l a hundred- or a 

 thousand-fold larger than those which were immediately poisonous 

 to him at the beginning of his experience. Therefore, in the case 

 of acute diseases and opium and nicotine, man has a means of 

 protection which is absent in the case of alcohol and chronic 

 complaints such as tuberculosis. Consequently a race that is for 

 the first time introduced to an acute disease or to nicotine or 

 opium does not start " from the scratch." It is advantageously 

 situated. It has undergone a previous evolution which, by 

 enabling it to acquire immunity, places it in a position of 

 advantage. In the case of tuberculosis and alcohol it has to 

 undergo an evolution which, in each instance, must be begun 

 almost at the beginning. Under severe modern conditions, the 

 races of the New World are able to survive acute diseases and 

 undergo evolution, but tuberculosis exterminates them. There- 

 fore, evolution against tuberculosis is much the more difficult and 

 tedious. Similarly, evolution against alcohol appears to be more 

 difficult than that against opium. An evolution of a few hun- 

 dreds of years has rendered the natives of India ' immune ' to 

 opium, but an experience of thousands of years has rendered the 

 British only in a measure immune to alcohol in the sense that 

 Italians are immune to it. 



516. Tobacco may be compared to chicken-pox. Nearly all 

 sufferers quickly and easily acquire immunity against this disease, 

 and all tobacco-smokers are moderate in the sense that they do 

 not desire to reproduce the immediately poisonous effects which 

 they felt as beginners. So few people perish from the one or the 

 other that no evolution results. Therefore races that have long been 

 afflicted by chicken-pox suffer as severely as races that are newly 

 exposed to it, while races that have long used tobacco indulge in 

 it as deeply as those who have had no previous experience. 



517. Opium may be compared to malaria. Malaria lies mid- 

 way between tuberculosis and chicken-pox. It is more acute than 



f~5 ! The power of acquiring a toleration does not, however, depend entirely on 

 the chemical complexity of the toxin. Thus, while it is said to be possible to 

 increase the toleration for arsenic, an absolutely simple substance, no appreciable 

 increase of toleration follows the use of many vegetable toxins, for example 

 digitalis and strychnine. See 413. 



