The greater or lesser frequency and force of the pulse in emotion depends upon the greater or lesser excitability of the nerve-centres. Women and children, who are more sensitive, experience this palpitation in greater intensity. When we say that women have more tender hearts, we refer to the fact that their hearts respond to stimuli to which the hearts of men remain impassive. We say of anyone who blushes and grows pale easily, and is soon moved to tears or laughter, that he has a good heart and a sincere character. But even cold, sceptical, egotistic, impassive men, when they are suffering from some illness, or when the excitability of their nervous system is intensified by some cause or other, may be deeply moved, and betray their feelings like children. One must be a physician in order to see how the most courageous men become faint-hearted at a trifling loss of blood, and timid people, in consequence of a more abundant flow of blood to the brain, perform miracles of bravery. Weakness quickens the heart-beat even when we are not moved by anything. We all know that we avoid giving certain news to the convalescent which at other times would have produced little effect upon them. One of my colleagues had been ill eight days from a quinsy. When he recovered and came to the laboratory, I hastened to visit him, and found him sitting in an arm-chair, pale and exhausted. I asked him how he was, to which he answered 'Very well,’ but that while scolding his servant on account of some trifling matter, such a feeling of oppression had seized him that he had to desist, as he was scarcely able to draw breath. I felt his pulse, and found that it was above a hundred. He laughed, and said, 'I never dreamt that my strong body was such a paltry piece of machinery as to run down during the few days I have not eaten as usual.’ VI