How fine, for example, are the observations made by Herbert Spencer concerning the importance of the “timbre” of speech in the light of the emotional state--no one had ever thought of that before, or considered the possibilities of gaining anything of importance from this single datum which has since yielded such a rich collection of completely proved and correctly founded results. Darwin knew well enough to make use of it for his own purposes.[75] He points out that the person who is quietly complaining of bad treatment or is suffering a little, almost always speaks in a high tone of voice; and that deep groans or high and piercing shrieks indicate extreme pain. Now we lawyers can make just such observations in great number. Any one of us who has had a few experiences, can immediately recognize from the tone of voice with which a new comer makes his requests just about what he wants. The accused, for example, who by chance does not know why he has been called to court, makes use of a questioning tone without really pronouncing his question. Anybody who is seriously wounded, speaks hoarsely and abruptly. The secret tone of voice of the querulous, and of such people who speak evil of another when they are only half or not at all convinced of it, gives them away. The voice of a denying criminal has in hundreds of cases been proved through a large number of physiological phenomena to do the same thing for him; the stimulation of the nerves influences before all the characteristic snapping movement of the mouth which alternates with the reflex tendency to swallow. In addition it causes lapses in blood pressure and palpitation of the heart by means of disturbances of the heart action, and this shows clearly visible palpitation of the right carotid (well within the breadth of hand under the ear in the middle of the right side of the neck). That the left carotid does not show the palpitation may be based on the fact that the right stands in much more direct connection with the aorta. All this, taken together, causes that so significant, lightly vibrating, cold and toneless voice, which is so often to be perceived in criminals who deny their guilt. It rarely deceives the expert.