Thirdly, there is the widespread error of ascribing the evils of the _abuses_ of tobacco to the _use_ of tobacco. This matter of the _use_ and _abuse_ of tobacco cannot be put too clearly. Most medical investigators have based their results clearly on the _excessive_ use of tobacco. It is a very rare thing to find a medical investigator drawing attention to any harmful results following the moderate use of tobacco, and it appears a just statement to make that the majority of men use tobacco in moderation. It appears to be true that excessive smoking is harmful and is capable of producing deleterious effects on the respiratory and nervous systems in man, but it has never been scientifically proved that the moderate use of tobacco has any particularly harmful effects. Moreover, it is well-known to the medical profession and so stated constantly that in many cases where the use of tobacco has produced bad effects on the eye, nerves, etc., its use is contra-indicated, owing to the condition of the subject due to other causes and that such results would not occur in a normally healthy subject. Therefore, because tobacco when used excessively or when used by persons who are not constitutionally fitted for it, produces bad effects, it is not logical to argue, as many opponents of tobacco smoking do, that the use of tobacco is universally harmful. Fourthly, the conclusions arrived at by some investigators, are based on experiments made on animals, and it appears quite open to criticism, and is in fact disproved by common experience, that such results will follow when applied to man. Hinging on this is the question of immunity and toleration. The human system will easily after use tolerate effects which at first it rebels against. This may easily be seen in muscular and other efforts. Let a man who is constantly leading a sedentary life suddenly walk 10 miles. The result is almost prostration and he will not recover from it for a considerable time. Let him, however, commence by walking a mile or two and gradually at each walk increase the distance, and in a short while he will be able to walk 10 miles without feeling any fatigue. Similarly running or other rapid exercise to a person not used to it will produce such rapid disturbances in the respiration and circulation as even to be fatal, while the seasoned athlete may perform such feats without the least ill effects. To take animals or persons who have never before used tobacco and to argue or conclude that the effects of tobacco smoke on them are the effects of tobacco on smokers generally is absurd. Yet such experimental results are very often made the basis of denunciation of tobacco smoking.