Let us not, however, indulge in sweeping statements. We have expressed ourselves with caution, but a still further limitation needs to be made. There are a few persons who are never stimulated, but always poisonously depressed, by certain particular narcotics. There are a few persons--ourselves among the number--in whom a very temperate dose of coffee will often give rise to well-defined symptoms of narcosis. There are others in whom even the smallest quantity of alcoholic liquor will produce giddiness and flushing of the face. And there are still others upon whom tobacco, no matter how minute the dose, acts as a narcotic poison. But such cases are extremely rare; and it is needless to urge that such persons should conscientiously refrain, once and always, from the use of the narcotic which thus injuriously affects them. Our friendly challenge, above given, is addressed to the vast majority of people; and thus limited, it may be allowed to stand. We have now defined a narcotic; we have seen that narcotics, in certain doses, will act as stimulants, and we have defined a stimulant. Until one's ideas upon these points are rendered precise, there is little hope of understanding the ordinary healthy action either of tobacco or of alcohol. But the reader who has followed us thus far will find himself sufficiently prepared for the special inquiry into the stimulant effects of these substances. Confining ourselves, for the present, to tobacco, we shall find that by assisting the nutritive reparatory process, it conforms throughout to the definition of a true stimulant.