When the vessels are cold unlute the receiver, and shaking it to make the Volatile salt, which sticks to it, fall to the bottom, pour it all into a bolt-head; fit it to a Head with a small receiver; lute well the junctures and placing it in sand, give a little fire under it, and the volatile salt will rise and stick to the head, and the top of the Bolt-head; take off your head and set on another in its place; gather your salt and stop it tip quickly, for it easily dissolves into a liquor; continue the fire, and take care to gather the Salt according as you see it appear; but when there rises no more salt, a liquor will distill, of which you must draw about three ounces, and put out the fire, "&c.    From Wordnik.com.  [Forty Centuries of Ink] Reference