The volatile salt therefore is by the mortifying acid spirits, as of Salt, Vitriol, Allom, Vinegar, _&c._ deprived of its volatility, and is fixed, by which means being debilitated it forsakes its associate which was infected with blackness by it: it is necessary that we should proceed after the same manner with these fetid Oyles, _viz._ as follows. Take any fetid Oyle of Tartar, Amber, _&c._ with which fill the fourth part only of a glass Retort, and upon it pour by drops the spirit of salt; and it will begin to be hot, as it is used to be, when Aqua fortis is poured on salt of Tartar; wherefore the spirit is to be poured on it by little and little, and by drops for fear of breaking the glass: Now the signe of the mortification of the volatile salt is, when it ceaseth to make a noise, and then no more is to be poured on, but set your Retort in sand, & give fire to it by degrees, as is used to be done in the rectifying things of easie elevation: and first of all will go forth a certain stinking water, after which comes a transparent clear, and odoriferous Oyle, and after that a certain yellow, clear, and also well smelling Oyle, but not so as the first, wherefore each must be taken a part by changing the receivers. Now these Oyles become more grateful than those fetid ones of the shops. For these Oyles retain their clearness, and fairness, the cause of their fetidness, and redness being taken away by the spirit of salt. In the bottom of the Retort remains the black volatile salt with the spirit of salt, from whence it may be sublimed into an odoriferous salt resembling salt armoniack in tast. The spirit of salt is also deprived of its acidity, and coagulated by the volatile salt, and is like _tartarum vitriolatum_, appointed also for its uses, as shall be spoken in the second part, of the spirit of Urine. After the same manner also are rectified other Oyles, which by length of time have contracted a clamminess, as are Oyle of Cinnamon, Mace, Cloves, _&c._ with the spirit of Salt, if they be rectified by Retort, for then they acquire again both the same clearness, and goodness, as they had when they were newly distilled.