Vials

In Act One, Scene Two of Richard the Second, the Duchess of Gloucester, attempts to compel her late husband’s brother, John of Gaunt, to stand with Gaunt’s son Bolingbroke and denounce the king for the act. She tells him,


Edward's seven sons, whereof thyself art one,
Were as seven vials of his sacred blood,
Or seven fair branches springing from one root:
Some of those seven are dried by nature's course,
Some of those branches by the Destinies cut;
But Thomas, my dear lord, my life, my Gloucester,
One vial full of Edward's sacred blood,
One flourishing branch of his most royal root,
Is cracked, and all the precious liquor spilt,
Is hacked down, and his summer leaves all faded,
By envy's hand and murder's bloody axe.

— 1.ii.11-21

She mixes metaphors here, on the one hand comparing each son of Edward III as “vials of his sacred blood,” while on the other as “fair branches springing from one root.” If Thomas (her late husband) is a vial, then he is “cracked, and all the precious liquor spilt;” if a branch, “hacked down.”

Why does she use such an awkwardly mixed comparison?

Thoughts?

I’m not sure…

Comment?