Alcohol is stimulating in its nature, because of its setting free from their usual control by the will the unconscious elements of the brain; while the effect of alcohol on the system as a whole is, as has been carefully proved by scientific investigation, unfortunate in every respect. Whether the alcohol be in the form of whisky or brandy or gin or in such milder forms as wines, beers, and hard cider, the continued use of even a small quantity acts adversely on the memory, on the will, on the intellect, on the inventive power, and on all the mental processes. It has a deteriorating effect on all the muscular tissue throughout the body, and while this is sufficiently deplorable, its effect on the mind is by far the more serious. No idea is more false than that a small amount of alcohol aids in the performance of work of any sort, and experience in the army, navy, and in exploring expeditions all go to show that the use of alcohol in any form reduces the capacity, both for activity and endurance. As a protection against cold, it is worse than useless, and the feeling of warmth which drinking alcohol in any form produces, does not manufacture heat in the body, but is rather a source of danger on account of the reaction of the whole system. _Tobacco._ The use of tobacco may or may not be injurious to the human system, and it is said by those accustomed to its use that it is for them a source of great enjoyment and comfort. The essential poison of tobacco is known as nicotine, and experiments are very readily made with this substance, extracted from the plant, to show its deadly character on the heart and nerve cells of animals. It is easy to demonstrate that the use of tobacco affects the heart, since the common "out-of-breath feeling" which comes to users of tobacco when climbing hills or running is well known. No young man training for an athletic event would think of smoking, on account of the danger to his wind. No boy should smoke, because nothing should be allowed to interfere with the fullest development of the heart and nervous system, and without question tobacco is a potent factor in influencing both. In many individual cases it has been shown that the use of tobacco in excess has a bad effect on digestion, while in other cases the trembling hand and inattentive mind indicate the result on the nervous system. No general law or rule can be laid down, and each man must act as his own individual constitution seems to require. _The drug habit._