After all Birds have been investigated and laid aside — Blue-stocking

After all Birds have been investigated and laid aside-1
Nature imparts the little Blue-Bird-assured
Her conscientious Voice will soar unmoved
Above ostensible Vicissitude.

First at the March-competing with the Wind-5
Her panting note exalts us-like a friend-
Last to adhere when Summer cleaves away-
Elegy of Integrity.
(F.1383/J.1395)
[1] Birds:: smart persons.
[2] Blue:: blue-stocking, a literary lady. assured:: this literary lady assured she is better than those smart men.
[4] vicissitude:: an unfriendly literature world for women.
[5] March:: advance; she started to fight. Wind:: rumor; twist.
[7] Summer:: peak, summit.

By the way, the origin of this term bluestocking has never been satisfactorily accounted for, unless the reader should incline to think my account satisfactory. I incline to that opinion myself. Dr. Bisset (in his Life of Burke) traces it idly to a sobriquet imposed by Mrs. Montagu, and the literary ladies of her circle, upon a certain obscure Dr. Stillingfleet, who was the sole masculine assistant at their literary sittings in Portman Square, and chose, upon some inexplicable craze, to wear blue stockings. The translation, however, of this name from the doctor's legs to the ladies' legs is still unsolved. ─ Beauties (1862) By Thomas De Quincey

Sir Joshua Reynolds, and many other men of taste and letters, highly esteemed Mrs. Montague, and even Burke thought favourably of her literary talents. Mrs. Montague and several other ladies, about this time, had evening assemblies, in which, instead of cards, they participated in the conversation of literary and ingenious men. One of the most eminent members, when the societies commenced, was Mr. Stillingfleet, who always wore blue stockings. As his conversation was very entertaining, they, when he was absent, used to say, we can do nothing without the blue stockings; and by degrees the assemblies were called blue stocking clubs. From that time those ladies, who are, or pretend to be, learned, or are in the fashionable circles supposed to be learned, are called blue stockings. ─ The life of Edmund Burke (1798) By Robert Bisset

I can hardly believe the origin of Blue-stocking in OED, no sense to name a literature gathering of women from one man's blue stockings. My view is, stocking as the sprouting of a plant, freely to the blue sky, being discomfited (blue) by the society in the 18th century.