57. Whether the Vein be every way of an uniform breadth, and thickness; and, if it be, what these Dimensions are; and if not, in what places it varies, and in what measures? (The like Questions are to be made concerning the sparre, Caulk, and other Teguments or mixtures of the Ore?)
58. Whether the Vein be un-interrupted, or in some places broken off; and whether it be abruptly, or not; and whether it be by Vales, Brooks, Gullets, &c?
59. How wide the Interruptions are? what Signs, whereby to find the Vein again? whether the ulteriour part or division of the Vein be of the same Nature, and hold on in the same Course, as to its tendency upwards or downwards, or Horizontally, Norward, Southward, &c. with the Vein, from which it is cut off?
60. Whether, in case the last end of the Vein be found, it terminate abruptly, or else end in some peculiar kind of Rock or Earth, which does, as it were, close or Seal it up, without leaving any crack or cranny, or otherwise? And whether the terminating part of the Vein tend upwards, downwards, or neither? And whether in the places, where the Vein is interrupted, there be any peculiar Stone or Earth, that does, as it were, seal up the Extremity of it?
61. Whether it be observed; that the Ore in Tract of time may be brought to afford any Silver or Gold, which it doth not afford, or more than it would afford, if it were not so ripe? And whether it have been found, that the Metalline part of the Vein grows so, that some part of the Mine will afford Ore or Metal in tract of time, that did not so before? And whether to this Maturation of the Mine, the being exposed to the free Air be necessary; or, whether at least it conduce to the Acceleration of it; or otherwise?
62. Whether all the Ore, contained in the Mine, be of the self-same nature and goodness; and, if not, what are the differing kinds; and how to be discriminated and estimated?
63. What is the fineness and goodness of the Ore, by which the Mine is wont to be estimated? And what are the marks and
characters, that distinguish one sort from another?
64. What proportion of Metal it affords? (As in our Iron-mines 'tis observed, that about three Tuns of Iron-stone will afford one Tun of Metal: And I have had Lead-Ore, which an Ingenious man, to whom I recommended such Tryals, affirm'd to me to afford three parts in four of good Lead.)
65. Whether the Ore be pure in its kind from other Metals, and, if not, of what Metals it participates; and in what proportion? Which is especially to be Inquired into, in case the Mine be of a base metal, that holds a noble metal: (As I have known it observ'd, that Lead-Ore, that is poor in its own metal; affords more Silver, than other; and I remember, that the Ore lately mention'd, being rich in Lead, scarce afforded us upon the Cuppel, an Atome of Silver. And Matthesius informs us, that a little Gold is not unfrequently found in Iron-Ore. And I have by me some Gold, that never endur'd the Fire, taken out of a Lump of Tin-Ore.)