Democritus Junior to the Reader, page 18

[p. 18]
Saturn was the lord of my geniture, culminating, etc., and Mars principal significator of manners, in partile conjunction with mine ascendant; both fortunate in their houses, etc.

Burton was quite planet-struck. An Anglican priest, he first delved into astrology to prove it was false, but instead grew fascinated with it. His studies led him to align the four humors with astrology:

Democritus Junior to the Reader, page 17

[p. 17]
...as long almost as Xenocrates in Athens...

Edward Bensly notes: "Xenocrates was head of the Academy for twenty-fives years (cf. Diogenes Laertius, Lives..., book IV, 2, 11). Burton had been a student of Christ Church for over twenty-one years when he published Anatomy)." (N&Q, 10th ser. vol. II, Dec. 3, 1904, p. 442). In another note Bensly comments again on the same passage: "The first edition [of Anatomy] has: 'that I haue liu'd a silent, solitary, priuate life, mini & musis in the Vniuersity this tuentie yeares, and more, penned vp most part in my study. And though by my profession a Diuine, yet...' Xeoncrates does not appear until the 3rd edition..." (N&Q, 10th ser. vol. VI, Aug. 25, 1906, p. 144).

Somehow, back then, being an "eternal student" wasn't a bad thing!

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... antistat mihi milibus trecentis [lit.: he excels me in 300,000 ways]

[Shilleto: Catullus, ix, 2]

Verani, omnibus e meis amicis
antistans mihi milibus trecentis...

Dear Veranius, of all my close companions
by three hundred miles the foremost...

(trans. Peter Green)

The slight divergences from the original suggest that Burton is quoting from memory!

Democritus Junior to the Reader, page 16

[p. 16]
My intent is no otherwise to use his name than Mercurius Gallobelgicus, Mercurius Britannicus, use the name of Mercury, Democritus Christians,* etc.;...

* R.B.: Auth. Pet. Besseo, edit. Coloniæ, 1616.

Mercurius was a brand of newspapers, or more properly, news books. The idea was copied after the Mercure française, launched in France in 1611. First to appear was the Mercurius  Britannicus, which in 1625 became the first English news periodical to carry that title.
(from Jonathon Green, The Vulgar Tongue: Green's History of Slang, Oxford University Press, 2011, p. 100)

The dates would seem to suggest that this name was thrown in in a later edition (Burton was a notorious re-writer).

Democritus Junior to the Reader, page 15

[p. 15]
[Edit. Feb. 29:]...that so insolently intrudes upon this common theatre to the world's view...

Edward Bensly notes that this comes from the dedication to a posthumous edition of Julius Caesar Scaliger's (1484–1558) Epistolae et orationes (Leyden, 1600), which read: "...aliqua scriptorum........quæ nondum communem theatri huius lucem aspexerant."

Jules César Scaliger was an interesting character: a page and protégé of Emperor Maximilian, he studied art under Albrecht Dürer. He fought with great valor in the battle of Ravenna in 1512, which claimed the lives of his brother and father. He then abandoned military life to pursue studies in Bologna. In 1525 he moved to Agen, as the physician to the noble Rovere family. He spent the rest of his life in that town, his reputation as a scholar and physician growing. In the 1520s, he was:

a majestic looking man of some forty years of age who was to become renowned as one of the greatest scholars of the Renaissance. ... [S]o great became his fame in all branches of learning that it was for long considered he was the greatest scholar who had ever dwelt in France.

Vernon Hall, Jr., Life of Julius Caesar Scaliger, in Transactions of the American Philosophical Society, new ser., vol. 40, part 2, 1950.

J.C. Scaliger, as well as his son, Joseph Juste, who managed to surpass his father in erudition, will be seen again and again in Anatomy...

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