But an industrious and accurate Physician is not ashamed to make his Medicines himself, if it be possible, or at least to have them made by good and well-exercis’d Artists: whereupon he may better rely, and get more credit, than one that knoweth not whereof, nor how his Medicine which he doth administer to his patients is prepared. But such wicked and ignorant men will one day fall short of their answer before the Judgment of the righteous Samaritan. _How to make the Acid Oyl and the volatile spirit of Vitriol._ Hitherto I have taught, how to distil in general, and to get the subtle spirits. There remaineth now to describe what Manuals or Preparations are fitting for every matter in particular; and first, _Of Vitriol._ To distil Vitriol, there needs no other preparation, but only that it be well viewed, and if there be any filth amongst it, that the same be carefully pickt out, lest being put together with the Vitriol into the distilling vessel, the spirit be corrupted thereby. But he that will go yet more exactly to work, may dissolve it in fair water, then filtrate it, and then evaporate the water from it till a skin appear at the top, and then set it in a cold place, and let it shoot again into Vitriol; and then you are sure that no impurity is left in it. Now your vessel being made red hot, with an Iron ladle cast in one or two ounces of your Vitriol at once, put on the lid, and presently the spirits together with the phlegm will come over into the receiver, like unto a white cloud or mist; which being vanished, and the spirits partly settled, carry in more Vitriol, and continue this so long, until your vessel be full: Then uncover your vessel, and with a pair of tongs or an iron ladle take out the Caput Mortuum, and cast more in; and continue this proceeding as long as you please, still emptying the vessel when it is filled, and then casting in more matter, and so proceeding until you conceive that you have got spirits enough. Then let the fire go out, and let the furnace cool; take off the receiver, and pour that which is come over into a retort, and set the retort in sand, and by a gentle fire distil the volatile spirit from the heavy oyl; having first joyned to the retort the receiver, which is to receive the volatile spirit, with a good lutum, such as is able to hold such subtle spirits, the making whereof shall be taught in the fifth part of this Book, amongst the Manuals.