FOOD for thought, indeed.

On my table at the Empire Cafe in the Briggait are inscribed lines from a poem by the British-Guyanese poet Fred D'Aguiar.

"They have white names and black faces./ Their hands turned Scottish industry/ Into British gold, their deaths passed/ like the toll of Sunday church bells."

The Empire Cafe - an interesting if temporary presence during the Commonwealth Games - has lots of these table inscriptions, all on the theme of slavery. The cafe, the work of novelist Louise Welsh and architect Jude Barber, explores Scotland's involvement with the North Atlantic slave trade, by means as diverse as tea, cake, poetry, walks and exhibitions.

As Yonder Awa, an anthology of poems given to customers, explains, the 1707 Act of Union gave Scottish merchants access to the Triangular Trade.

Goods were shipped to Africa's West Coast in exchange for men, women and children, who were taken across the Atlantic and sold for labour on plantations across the New World; the ships were laden with sugar, cotton and tobacco, all highly prized items in Europe.

Glasgow played its part in these slave-trade journeys, sending 31 recorded voyages between 1706 and 1766.

As Welsh observes in Yonder Awa, reminders of Scotland's involvement are all around us - in, for example, the ginger that spices the sugary cakes we wash down with tea or coffee. "Profits from Scotland's involvement in the triangular trade also remain in some of our finest buildings," she adds. Glasgow's Merchant City was built with profits from sugar, cotton and tobacco, made by merchants who owned and worked slaves.

In time, however, the city went from being economically dependent on slave labour to a seat of abolitionist activity.

This complexity is reflected in a series of Emancipation Acts - outdoor performances at significant locations across the city centre.

Ramshorn Kirk, for example, is where a number of colonial merchants are buried. While the City Halls witnessed speeches by prominent abolitionists such as Frederick Douglass, Virginia Court once hosted an auction house for produce brought from the New World.

The performances begin in the Briggait, where five actors - Ncuti Gatwa, Ross Mann, Martin McBride, Lou Prendergast and Paksie Vernon - lay bare some of the facts of the slave trade.

References are made to appallingly overcrowded slave ships, on which the air "soon became unfit for respiration". The groans of the dying mingle with the shrieking of women.

At various points on the walks we hear from slaves, a female abolitionist and two prosperous merchants, all discussing different aspects of the trade.

The abolitionist speaks passionately of the need to abolish slavery from across the territories of the British Empire. The cynical merchants concede slavery can be cruel but insist that life itself is full of unavoidable cruelties.

In the audience is Frank Boyd, who developed Glasgow's Black History Month "slave walks". "It's an interesting and imaginative way of presenting this story," he says, admiringly.

Today is the last day of the Empire Cafe and the performances.

On Glasgow Green there's an Emancipation Day carnival, with historian Sir Tom Devine among those taking part in a discussion at 5pm.