Urban myth - decomposing granite causes malarial fever

Though the medical men of the day pooh-poohed the idea, this urban myth was spread so far that it held up for at least 50 years.

1844 - Friend of China 30.3.44 edition

"M/s Milne and Vesey are contracted to government to fix the drains but week after week nothing is done and now the hot weather is almost upon us. They should not turn over the soil now and expose us to the noxious disease-causing fumes in the decomposing granite subsoil. We prefer instead to rely on the Police Superintendent sluicing the drains daily."

1853 - China pictorial, descriptive, and historical. - Miss Corner (Julia)

The rocks, which constitute the whole soil, are composed of rotten decomposing granite, which, as is well known (and was well known long before our men in authority took it as a settlement), is as productive of gases and malaria as any bad jungle in India. Scarcely a single man in our service, whether European, Indian, Malay, or Macao Portuguese, has passed any time on the island without suffering most severely in health. The Chinese have always regarded the place as fatal to human life, and they will not continue there beyond a certain season.

1860 - The London Lancet

"it is well known amongst the Chinese that the excavation for a foundation leaves an unhealthy odor for some time, and unless exposed to the atmosphere and sun, would induce fever; and no Chinaman will sleep on a ground floor at Hong-Kong if he can help it."

1898 - An American cruiser in the East;

Hong-kong is not a healthy place. Malaria is given out from its decomposing granite hills

A biographical sketch-book of early Hong Kong

of Hong Kong may be briefly summarized as follows: the precipices and rocky ravines would always prevent the growth of a large town; the decomposing granite and disintegrating sandstone emitted a foetid odour productive of disease, ...