dy, there is a greater power and
vertue."

In the 1588 edition of Baptista Porta's _Magiae Naturalis Libri xx._, in
lib. vii., cap. xviii., occurs the description of the use of the balance to
which Gilbert refers.

[157] PAGE 67, LINE 21. Page 67, line 22. _aeris rigore._--All editions
read thus, but the sense seems to require _frigore_.

[158] PAGE 67, LINE 27. Page 67, line 31. _Fracastorius._--See his _De
Sympathia_, lib. i., cap. 5 (Giunta edition, 1574, p. 60).

[159] PAGE 68, LINE 5. Page 68, line 6. _Thaletis Milesij._--See the note
to p. 11, line 26.

[160] PAGE 68, LINE 30. Page 68, line 35. _Ita coitio magnetica actus est
magnetis, & ferri, non actio vnius._--See the introductory remarks to these
notes. There is a passage in Scaliger's _De Subtilitate ad Cardanum_
(Exercitat. CII., cap. 5, p. 156 _op. citat._) which may be compared with
Gilbert's for its use of Greek terms: "Na cum uita dicatur actus animae,
acceptus est abs te actus pro actione. Sed actus ille est [Greek:
entelecheia], n[~o] autem [Greek: ergon]. At Magnetis attractio est [Greek:
ergon], non aut[~e] [Greek: entelecheia]." To which Gilbert retorts: "non
actio unius, utriusque [Greek: entelecheia]; non [Greek: ergon], [Greek:
sunentelecheia] et conactus potius quam sympathia." He returns on p. 70 to
the attack on Scaliger's metaphysical notions. There is a parallel passage
in the _Epitome Naturalis Scientiae_ of Daniel Sennert (Oxoniae, 1664), in
the chapter _De Motu_.

[161] PAGE 71, LINE 4. Page 71, line 8. _vt in 8. physicorum Themistius
existimat._--See _Omnia Themistii Opera_ (Aldine edition, 1533, p. 63),
Book 8 of his Paraphrase on Aristotle's _Physica_.

[162] PAGE 71, LINE 9. Page 71, line 14. _Quod vero Fracastorius._--_Op.
citat._, lib. i., cap. 7, p. 62 _verso_.

[163] PAGE 73, LINE 2. Page 73, line 2. _si A borealis._--The editions of
1628 and 1633 omit the twelve words next following.

[164] PAGE 73, LINE 9. Page 73, line 11. _ex minera._--_Minera_ is not a
recognized word, even in late Latin. It occurs again, p. 97, line 12.

[165] PAGE 77, LINE 2. Page 77, line 2. _multo magis._--This is an _a
fortiori_ argument. It is interesting to find Gilbert comparing the
velocity of propagation of magnetic forces in space with the velocity of
light. The parallel is completed in line 13 by the consideration that as
the rays of light require to fall upon an object in order that they may
become visible, so the magnetic forces r