A letter from Robert Burns describing a lads' night out is going on display for the first time in more than 100 years.

It was sent in August 1786 after the poet spent a rowdy evening in Maybole, Ayrshire, with school friend William Niven.

The letter was bought at auction last year by the National Library of Scotland and will go on display on Thursday to celebrate Burns Night.

Burns wrote: "I thank you with the most heartfelt sincerity for the worthy knot of lads you introduced me to.

"Never did I meet with so many congenial souls together.

"To each and all of them make my most friendly compliments particularly spunkie, youthful Tammie."

However, the Bard of Ayrshire suggests he may have misbehaved towards "two truly worthy old gentlemen".

"I am afraid the conduct you forced me on may make them see me in a light I would fondly think I do not deserve," he told Niven.

The meeting between the pair happened weeks after the publication of Burns' first work, Poems Chiefly in the Scottish Dialect.

Despite his later popularity, he cautioned Niven: "Never blaze my songs among the million, as I would abhor to hear every prentice mouthing my poor performances in the streets."

The National Library said the letter, which had been held in private hands since 1899, was an important addition to its collection.

Meanwhile, National Records of Scotland plans to display correspondence providing an insight into how Burns was viewed by his contemporaries.

They were addressed to one of his most important patrons, Robert Graham of Fintry.