IV. _Of the Different Qualities of Od in different individuals._—Von Reichenbach observed the Od light to have different colours under different circumstances, and that, while Od-negative produces the sensation of a draft of cool air, Od positive produces a sense as of a draft of warm air. An easy way to verify the last phenomenon is to beg some one to hold the forefinger of the right hand pointed to your left palm, at a quarter of an inch distance, and afterwards his left forefinger to your right palm, when the two sensations, and their difference, are appreciable by the majority of persons. Persons entranced by mesmeric procedures are often keenly alive to the above impressions. They see light emanating from the finger-tips of the mesmeriser, and feel an agreeable afflatus from his manipulations. Others who approach them affect them in different ways—some not disagreeably, while others excite a chilly, shivering feeling, and the patient begs they will keep off from him. A gentleman narrated to me the following case. He had been for months in anxious attendance upon a brother who was in very delicate health, and exquisitely sensitive to mesmerism. My friend used himself to mesmerise his brother; but he found it necessary, in order to soothe and not excite him by the passes, to cover the patient with a folded blanket, so as to dull the agency of his Od-emanation. There was but another person, of several who had been tried, whose hand the brother could bear at all; this was a maid-servant, who herself was highly susceptible, and became entranced. She said that she perceived, when entranced, the suitableness of her influence, and that of the brother, to the patient; and she used the singular expression, that they were nearly of a colour. She said that the patient’s Od-emanation was of a pink colour, and that the brother’s was a brick colour—a flatter, deeper, red; and she endeavoured to find some one else with the same coloured Od to suit her master. In some experiments made at Dr. Leighton’s house in Gower Street, I remember it was distinctly proved that each of the experimenters produced different effects on the same person. The patient was one of the Okeys, of mesmeric celebrity. The party consisted of Dr. Elliotson, Mr. Wheatstone, Dr. Grant, Mr. Kiernan, and some others. Mr. Wheatstone tabulated the results. Each of us mesmerised a sovereign; and it was found that on each trial the trance-coma, which contact with the thus mesmerised gold induced, had a characteristic duration for each of us. Is it possible that each living person has his distinguishable measure of Od, either in intensity or quality? * * * * *