t part they are constrained to hang by ropes that shall get it
forth."

[122] PAGE 48, LINE 18. Page 48, line 20. _Similes etiam attrahendi vires
habere videntur vitrum ... sulphur, mastix, & cera dura sigillaris._ If, as
shown above, the electric powers of diamond and ruby had already been
observed, yet Gilbert was the first beyond question to extend the list of
_electrics_ beyond the class of precious stones, and his discovery that
_glass_, _sulphur_, and _sealing-wax_ acted, when rubbed, like amber, was
of capital importance. Though he did not pursue the discovery into
mechanical contrivances, he left the means of that extension to his
followers. To Otto von Guericke we owe the application of sulphur to make
the first electrical machine out of a revolving globe; to Sir Isaac Newton
the suggestion of glass as affording a more mechanical construction.

Electrical attraction by natural products other than amber after they have
been rubbed must have been observed by the primitive races of mankind.
Indeed Humboldt in his _Cosmos_ (Lond., 1860, vol. i., p. 182) records a
striking instance:

"I observed with astonishment, on the woody banks of the Orinoco, in the
sports of the natives, that the excitement of electricity by friction was
known to these savage races, who occupy the very lowest place in the scale
of humanity. Children may be seen to rub the dry, flat and shining seeds or
husks of a trailing plant (probably a _Negretia_) until they are able to
attract threads of cotton and pieces of bamboo cane."

[123] PAGE 48, LINE 23. Page 48, line 25. _arsenicum_.--This is _orpiment_.
See the _Dictionary of metallick words_ at the end of Pettus's _Fleta
Minor_.

[124] PAGE 48, LINE 23. Page 48, line 26. _in convenienti coelo
sicco_.--The observation that only in a dry climate do rock-salt, mica, and
rock-alum act as electrics is also of capital importance. Compare page 56.

[125] PAGE 48, LINE 27. Page 48, line 31. _Alliciunt haec omnia non
festucas modo & paleas._--Gilbert himself marks the importance of this
discovery by the large asterisk in the margin. The logical consequence was
his invention of the first _electroscope_, the _versorium non magneticum_,
made of any metal, figured on p. 49.

[126] PAGE 48, LINE 34. Page 48, line 36. _quod tantum siccas attrahat
paleas, nec folia ocimi._--This silly tale that basil leaves were not
attracted by amber arose in the _Quaestiones Convivales_ of Plutarch. It is
repeated b