person suffering from it was a user of tobacco 

 and to allege, therefore, that tobacco was the 

 cause of the condition. It must be shown con- 

 clusively that no other circumstances than the 

 use of tobacco could have caused this condition. 

 Dr. T. W. Jenkins, of Albany, N. Y., (New 

 York Medical Journal, 1915, V. 102, p. 355), 

 who was awarded a prize by this leading medical 

 journal for his essay on tobacco smoking says: 

 "The first thing to bear in mind is that con- 

 sidering the large amount of tobacco used very 

 little harm results, and care should be taken 

 not to incriminate tobacco when the troubles 

 under observation may be due to other causes." 

 Secondly, among the investigators themselves 

 who have made impartial inquiries about the 

 effects of tobacco, there is sometimes a wide dif- 

 ference of opinion in the interpretation of re- 

 sults and in the relation of cause and effect. 

 Thus most varied opinions exist on the subject 

 of nicotine. The result is that it is difficult for 

 the average man to come to a satisfactory con- 

 clusion on the subject; for it cannot be said 

 that the scientific knowledge of the effects of 

 tobacco smoking on the human system as pre- 

 sented to us today is final or sufficiently well 

 determined to enable definite and true conclu- 

 sions to tie arrived at. 



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