Scottish fact of the day: William Cullen, inventor of refrigeration

THE first recorded instance of artificial refrigeration was unveiled by physicist and chemist William Cullen (1710-1790) in the mid-18th century.

Cullen demonstrated his discovery at Glasgow University in 1748, although no proposal was made to commercialise the technique at the time.

The Hamilton-born scientist achieved the effect of refrigeration by boiling ethyl ether in a partial vacuum.

It was only in the 19th century that freezing became a commonplace method of preserving perishable goods such as meat, a development which coincided with innovations in electrical motors that replaced more primitive ways of transporting food via ships over long distances.

An estimated 500 million fridge-freezer units are now used worldwide.