“Malaria” is derived from the Italian words for “bad air” (mal = bad, aria = air), which for a long time was the suspected cause of the disease. It wasn’t until 1880 – many years after the completion of the canal – that scientists discovered the true source of malaria was not poor air quality at all, but parasites found inside blood cells. The canal construction zone, located as it was in a densely forested and swampy area, was prime real estate for swarms of mosquitoes, which multiplied during the hot and humid summer months and transmitted the disease. In an effort to curb instances of infection, Lt. Col. By ordered the densely forested land around the lock stations to be cleared – not to reduce the number of mosquitoes, of course, but rather to improve the overall air quality of the construction zone. Since this strategy was based on a fundamental misunderstanding of what caused malaria, every year the disease would resurface, each time with devastating results. If victims of malaria were lucky enough to survive – and many hundreds weren’t – their journey back to health was painful and exhausting, leaving them tired, weak, and likely unable to return to work.

Points of Interest

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[Source: MacTaggart, John. Three years in Canada : an account of the actual state of the country in 1826-7-8, comprehending its resources, productions, improvements, and capabilities, and including sketches of the state of society, advice to emigrants, &c. London : H. Colburn, 1829.Carleton University Archives and Research Collection. RAR FC51.M28 v.1/v.2]

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A Personal Account of Malaria

In his first-hand account of how malaria ravaged the mind and body, surveyor (and malaria survivor) John MacTaggart wrote vividly of the disease:

“The fever and ague of Canada are different, I am told, from those of other countries; they generally come on with an attack of bilious fever, dreadful vomiting, pains in the back and loins, general debility, loss of appetite, so that one cannot even take tea, a thing that can be endured by the stomach in England when nothing else can be suffered. After being in this state for eight or ten days, the yellow jaundice is likely to ensue, and then fits of trembling … For two or three hours before they arrive, we feel so cold that nothing will warm us; the greatest heat that can be applied is perfectly unfelt; the skin gets dry then the shaking begins. Our very bones ache, teeth chatter, and the ribs are sore, continuing thus in great agony for about an hour and a half; we then commonly have a vomit, the trembling ends, and a profuse sweat ensues, which lasts for two hours longer. This over, we find the malady has run one of its rounds …”

Watercolour showing Lt. Col. By watching the building of the Rideau CanalEnlarge

[Source: Colonel By Watching the Building of the Rideau Canal, 1826. Charles William Jefferys, Imperial Oil Collection series, Library and Archives Canada, accession number 1972-26-795, C-073703]

Malaria Outbreak

Disease was a constant fact of life during the entire construction period, but in the summer of 1828 the most severe malaria outbreak brought work to a halt at many lock stations along the Rideau. While construction continued slowly at the Bytown locks, Lt. Col. By himself (depicted here supervising construction) contracted the disease and had to be nursed slowly back to health by Board of Ordnance Surgeon Dr. M. H. Tuthill.


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[Source: Library and Archives Canada, MG13-WO44, volume 16, pages 72-74]

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Labour Turnover

The canal workforce wasn’t depleted just by the loss of those who actually caught malaria. Desertion rates skyrocketed, particularly during the 1828 outbreak, as healthy workers fled the dreaded disease, to the extent that some sites, such as the hard-hit Isthmus lock station, experienced a massive turnover of their labour force. Desertion became such an issue that Lt. Col. By even offered the Royal Sappers and Miners incentives of their own 100-acre (40-hectare) plot of land if they stayed on until the end-and even that wasn’t always enough to convince them to stay. As this document shows, an estimated 35 of the 160 Sappers and Miners working on the canal abandoned their posts before construction was complete.

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