joking about a tournure

SCENES BEYOND THE WESTERN BORDER

The girls must consider as a lively feature of this dull region, (or they are not common girls). For our part, it is reported that one of them has been seen actually—that is, evidently invested with a "tournure"; who would believe the tyrant Fashion held so wide a sway!

-- Scenes Beyond the Western Border - May 1852; and Scenes and Adventures in the Army

MELVILLE'S CORRESPONDENCE

They heard that you had begun to take to — drink? — Oh no, but worse — — to sonnet-writing. That off Cape Horn instead of being on deck about your business, you devoted your time to writing a sonnet on your mistress’ eyebrow, & another upon her “tournure”. 

-- Herman Melville, May 25, 1862 letter to his brother Thomas Melville in the 1993 Northwestern-Newberry Edition of Melville's Correspondence, edited by Lynn Horth, page 378.

leaves it for the commentators

"Indeed, the settlement of this question must be left to the commentators on Mardi, some four or five hundred centuries hence."  (Mardi)

... and finally, in despair, he "imitated humanity so abominably," as to throw himself headlong, and so drown—or hang himself:  (the author cannot decide which —even after a post-mortem examination;—and so leaves the decision of this important point to the commentators.)
("Scenes Beyond the Western Border," March 1853; and
Scenes and Adventures in the Army)

mathematical machines

"And not more infallible the ponderings of the Calculating Machine than the deductions from the decimals of history."  (Mardi)

"Woman generally lacks that mathematical element, which in man, makes him often a little superior to some admirable machines...." 
("Scenes Beyond the Western Border," June 1852; and
Scenes and Adventures in the Army)

masses indifferent to biology and botany

And how many millions there are who live from day to day by the incessant operation of subtle processes in them, of which they know nothing, and care less?  Little ween they, of vessels lacteal and lymphatic, of arteries femoral and temporal; of pericranium or pericardium; lymph, chyle, fibrin, albumen, iron in the blood, and pudding in the head.... (Mardi)

F.—With what strange complacency does the mass of even the 'educated,' ignore the charming mysteries of botany!  They may be surprised into admiration of a fine flower; but it is a mere sensation,

                               ' —the smallest part
Exceeds the narrow visions of their minds.'

C.— "And they lose half the beauty, which, such is their perfection, they reveal to minute examination."

"Scenes Beyond the Western Border," August 1852; and
Scenes and Adventures in the Army