John Macdonald of Ferintosh – the Apostle of the North – was one of the most famous ministers in the North of Scotland in the 19th century. His sphere of labour extended far beyond his own parish and included evangelistic tours to the remote Atlantic islands of St Kilda. Books and pamphlets containing sermons, lectures and poems of Dr Macdonald are long out of print and some are extremely scarce. This first volume of his Collected Works also includes material which has never before been published. The title of the book alludes to a moving sermon Dr Macdonald preached at the height of a cholera pandemic. Printed here for the first time in English translation, the ‘Cholera sermon’ demonstrates the intense pastoral concern Dr Macdonald showed for the souls and bodies of his hearers. His sound advice is just as applicable to present-day readers as it was then: ‘Do thyself no harm.’