About the sixth Title.
66. What are the mechanick and prævious Operations, as Beating, Grinding, Washing, &c. that are used to separate the Ore from the Heterogeneous Bodies, and prepare it for the Fire? Or whether the Ore requires no such preparation? (as it often happens in Lead, and sometimes in Iron, &c.)
67. Whether Mercury be made use off, to extract the nobler from the baser metals? (as is their practice in Peru, and other parts of the West-Indies.)
68. Whether the leaving the Ore expos'd to the open Air and Rain for a good while, be used as a Præparative? (as I have seen done in Iron-stone.)
69. Whether the Burning and Beating of the Ore be used to prepare it for the Furnace? (as is practised in Iron, and almost always in Copper:) And, in case they use it more than once, how often they do it; (for, Copper-Ore is in some places washed 8. or 10. times, and in others, 12. or 14.) and with what circumstances; as, how long the Ignition lasts at a time, whether the Ore be suffer'd to cool of it self, or be quench'd? whether it be washed betwixt each Ignition?
70. What Flux-powders, and other ways they have to try
and examine the goodness of the Ore in small quantities?
71. Whether, when they work in great, they use to melt the Ore with any Flux or Additaments, or only by the force of the Fire, or in any way between both? (As throwing in of Charcoals when they melt Iron-stone does not only serve to feed the Fire, but perhaps by the Alchaly of its Ashes to promote the fusior: so Lime-stone, &c.)
72. What kind of Furnaces they use, to melt the Ore in? Whether they be all of one sort and bigness, or of differing?
73. What are, the Situation, Materials, Dimensions, Shape, Bigness, and in short what is the whole structure and Contrivance of the Furnace? If there be any thing peculiar and remarkable? What Tools are used in Smelting, their Figures, use, &c. And the whole manner of working?