178 THE WONDERFUL HOUSE THAT JACK HAS 



to the too rapid and irregular beating of the heart 

 which is sometimes caused by the narcotic effect of 

 tobacco on the nerves. In such cases, if smoking is 

 given up for a time, the heart's action soon becomes 

 normal ; but, if the harmful habit is continued in spite 

 of such warning, serious injury may be done. Often 

 men whose employment makes very little physical 

 exercise necessary, have not realized the weak condi- 

 tion of their heart until refused life insurance on this 

 account. 



In a magazine article published February, 1897, 

 Professor J. W. Seaver, Director of Yale University 

 Gymnasium, gave some remarkable information con- 

 cerning students who were tobacco users. For nine 

 years he had kept careful record of the age, height, 

 weight, chest girth, and lung capacity of all stu- 

 dents who entered that university. He also recorded 

 whether they had used tobacco before coming to 

 college. According to his records, the smokers who 

 entered Yale during that period averaged fifteen 

 months older than those who were non-users of tobacco. 

 This would certainly seem to prove that the tobacco 

 habit hinders boys from making their best progress 

 in school. 



The measurements he made of the students who 

 entered, showed that while the smokers were, as a rule, 

 somewhat heavier, their average height and lung 

 capacity were both considerably smaller. Now as 

 they were, on the average, fifteen months older, they 



