Dispelling Some Myths: Romans knew about bacteria

‘10 modern things the Romans had’ is a YouTube video created and hosted by Raffaello Urbani, who is otherwise known as ‘Metatron’. His channel is well worth watching if, like me, you are interested in such things as languages, video games, historic arms and armour, and medieval history. Maybe not the video games, but being Italian Metatron has a special interest in the ancient Romans, which is one of the reasons I subscribe to the channel. In this particular video it was stated at the 15:45 minute point that ‘the Romans knew about bacteria’. What? How could they?

As evidence Metatron quotes Marcus Terentius Varro’s book ‘On Farming’  (De re rustica, 1.12.2):

‘Precautions must also be taken in the neighbourhood of swamps, both for the reasons given, and because there are bred certain minute creatures which cannot be seen by the eyes, which float in the air and enter the body through the mouth and nose and there cause serious diseases.’

But how could Varro be aware of micro-organisms invisible to the human eye? Most probably his knowledge stems from observing that some people became sick when near to swamps where clearly detectable foul-smelling air would have been breathed in. If enough people are observed to get ill, then Varro’s deduction makes sense. Yet the reference to what has been translated as ‘minute creatures’ does not necessarily mean the Romans knew about bacteria. It may be just Varro’s simple analogy to explain the connection to a general readership.

The quoted extract does not explicitly talk of ‘bad air’ but an inferred connection to ‘malaria’ is equally clear. The disease, now known to be mosquito-borne, once was thought to be caused by foul air in marshy districts. Yet, once again, this appears not to be a term used by the Romans to describe swamp related illnesses. It would be correct to say the Italian word mal'aria is derived from ‘mala aria, literally meaning ‘bad air’, a combination of mala ‘bad’ (fem. of malo, from Latin malus) plus aria ‘air’. But again this is not necessarily a term recognised by ancient Romans. Rather, ‘malaria’ was probably first used by Italian physician Francisco Torti (1658-1741; pictured). By 1866, however, the word was being applied to the disease itself, superseding the earlier term ‘malaria fever’.

Of note, the accepted history of bacteriology began in Torti’s lifetime. In 1676 the Dutch microscopist Antonie van Leeuwenhoek is credited with being the first person to observe bacteria by using a single-lens microscope of his own design. His observations were published in a series of letters to the Royal Society in London. The important point is the microscopic nature of bacteria required, unsurprisingly, the invention of the microscope before they could be discovered, studied and understood. The microscope, suffice to say, is not something ‘the Romans ever did for us’. QED.