But what constitutes moderation or the reverse? The answer is idiosyncrasy, or the degree of toleration. This is a factor which is lost sight of by most of those who declaim against the occasional glass or pipe. They wish to push temperance to the point of total abstinence, and condemn the man who takes a peg of whisky without evil results, with the man who becomes maudlin after taking a single glass of white wine, for it is only by outward appearances they are able to judge. But leaving them to rage in their ignorance, we must recognise the fact that opium is one of those drugs the effects of which depend largely upon personal idiosyncrasy and toleration. Dr. Chapman, in his _Elements of Therapeutics_, gives two instances of remarkable cases of toleration of opium. In one, a wineglassful of laudanum was taken by a patient several times in the twenty-four hours; and in another, a case of cancer, the quantity of laudanum was gradually increased to three pints daily, a considerable quantity of crude opium being also taken in the same period! The usual dose, as a medicine, is from one to three grains of opium, but a consumer can take from ten to twenty, while I have met many able to take from sixty to eighty grains. The degree of tolerance is increased by usage and habit, and the tendency is to increase the dose with habituation. With smokers, it is not uncommon to find Chinamen, the heaviest consumers of opium in the world, who can dispose of three tolas[5] of opium in the day; but they smoke it, and so can stand far more of it than if they ate it in the crude state.