A perusal of the vast amount of literature both for and against the use of tobacco brings out certain points very largely. First, in the case of the opponents, the most sweeping statements are made without a particle of scientific proof in support of them, by persons who are in no way qualified to make such statements. Statistics are quoted most recklessly and accepted as conclusive, although in most cases there is no logical connection between the matter of the statistics and the absolute effects of tobacco. If there is a question of a certain condition, it is not sufficient to show that the 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 conclusively 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 considering 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 difference of opinion in the interpretation of results 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 conclusion on the subject; for it cannot be said that the scientific knowledge of the effects of tobacco smoking on the human system as presented to us today is final or sufficiently well determined to enable definite and true conclusions to be arrived at.