Alludes to the identity of the Stone of the Philosophers, declaring that it is "cast down in every place", that it is single in its essence yet diverse in its manifestations, and that the alchemical process is brought to completion solely by that which resides within it. Explains that the water which is extracted from it, which has been called mercury and which is the key of the operation, nurtures the earth of the stone until the red sulfur, which was concealed within the earth, rises to the surface through the power of the water. Reveals that the red sulfur, which has been called by many names, is the essence of the active agent (jawharu'l-fa'il), the activity of which "astounds the hearts of those who have attained". Enjoins those who have discovered the secret not to make it for themselves. Accuses Mirza Yahya of producing false treatises on the subject based on what he had heard, and misunderstood, from Baha'u'llah's many Tablets on the subject.