21st August 1835

Mapmaking geologist John MacCulloch died

Guernsey-born John MacCulloch is credited with introducing the word “malaria” into the English language.

His lengthy essay on the illness didn’t entirely pin the blame on mosquitos. He wrote, “this is the unseen, and still unknown poison to which Italy applies the term that I have borrowed, Malaria”.

He described it as an “unknown agent of disease [to which] the term marsh miasma has been applied” because it was common among the “lower orders” of people – likely to work the land – in “France, Italy, Holland and elsewhere, and not less known to at least our own rural population… since every labourer in Lincolnshire or Essex believes that his ague is the produce of the fens”.

However, aside from that addition to the English language, his greatest contribution to our understanding of the world around us was his surveying and map-making.

A life on the mainland

As his name would suggest, MacCulloch was half Scottish. The rest of him was Sarnian, but he didn’t spend much of his life on Guernsey. After qualifying as a medical doctor in Edinburgh, he joined the Geological Society of London. He also taught at the Royal Military Academy.

In 1811, aged 38, he wrote a paper on the geological structure of Guernsey. The subject matter hinted at the field of interest which would consume much of the rest of his life.

He moved to Scotland to perform a wide range of geological surveys and experiments. There, he produced an extensive “Description of the Western Islands of Scotland, including the Isle of Man”.

In 1826 the government contracted him to draw up a geological map of Scotland. This task consumed every summer from them until his death in 1835. Although he completed the task just before he died, it wasn’t published until the following year.

He was 61 when he died in hospital in Cornwall, having broken his leg on his honeymoon. The leg had had to be amputated and he succumbed a few days later.