Then & now: Spitting images
Once considered socially acceptable, the nauseating public health hazard has all but died out in Hong Kong.
Public spitting more resolutely divides Hong Kong Chinese from their cross-border brethren than any other attribute. This social marker illustrates profound social differences between citizens here and in the rest of China, and signals very different approaches to civic hygiene and general public life.
Instances of mainland toddlers relieving themselves in the gutter remain uncommon enough that filmed examples posted online quickly go viral. Far more commonplace is the rasping hawk of a throat being cleared or the stomach-churning sight of someone leaning forward, index finger firmly pressed to one nostril while the bunged-up contents of the other are blasted forth onto the pavement.
The health risks posed by these foul habits are well-known. Anti-spitting campaigns have been the subject of public health crusades since Western medical science in the 19th century conclusively linked the expectoration-caused transmission of mucus, saliva and aerosol-borne germs with the rapid spread of epidemic disease.
Victorian public education drives against spitting - combined with punitive fines - continued into the 20th century and gradually achieved widespread success in many parts of the world.
Tuberculosis, a scourge of humanity for millennia, was eventually brought under control.
By 1938, two-fifths of all Hong Kong deaths were still attributable to tuberculosis, bronchitis and pneumonia, all of which were spread by public spitting.
Western visitors were shocked and revolted enough by this practice to write about it in nauseated terms. Travel accounts not only from Hong Kong and China, but right across the Chinese diaspora, all mention the prevalence of hacking, hocking and hawking.