How did Americans know to use smallpox infected blankets, before germ theory?

Question

How did Americans know that Native Americans would be infected with smallpox, from smallpox infected blankets, hundreds of years before germ theory?

Answer 1

Before germ theory, there were similar concepts of infectious disease- bad humors, bad air, etc. Miasma theory held that decaying organic matter transmitted infectious fumes to other organic matter. Girolamo Fracastoro went further and developed a proto-germ theory in the 1500s. So people got the idea.

Answer 2

They knew about "variolation":

Variolation was the method of inoculation first used to immunize individuals against smallpox (Variola) with material taken from a patient or a recently variolated individual, in the hope that a mild, but protective, infection would result. Only 1–2% of those variolated died from the intentional infection compared to 30% who contracted smallpox naturally. Variolation is no longer used today. It was replaced by the smallpox vaccine, a safer alternative. This in turn led to the development of the many vaccines now available against other diseases.

So they knew that the contact with infected material could span the contagious.

The use of variolation to try to prevent the spread of the disease span from 1600:

Letters from physicians in Wales published in 1722 indicated the local use of variolation from as early as 1600 near the Welsh port of Haverfordwest. Another reference to variolation is by Thomas Bartholin in 1675.

For the USA, documentation of variolation in the Americas may be traced back to 1706:

Documentation of variolation in the Americas may be traced back to 1706 in Boston, where Puritan minister Cotton Mather learned of the technique from his West African slave Onesimus.  Further research into the matter revealed to Mather that several other slaves had too been variolated. In 1714, he came across Timoni's article in Philosophical Transactions, in which he described methods of variolation found in Turkey. Mather was able to implement this new method in 1721 when Boston suffered a smallpox outbreak, although others such as William Douglass strongly opposed the idea.

On a side note, you may see the use of variolation in the John Adams tv series

Answer 3

How did Americans know that Native Americans would be infected with smallpox, from smallpox infected blankets, hundreds of years before germ theory?

Did Americans know or merely hope that Native Americans would be infected with smallpox, from smallpox infected blankets?

Apparently smallpox can be spread by infected objects even though it usually spreads by airborn viruses from infected persons.

Certainly British commander in North America Lord Jefffrey Amherst hoped that giving Native Americans blankets from smallpox victims would infect them.

But wiser persons might have warned him that his evil and genocidal plan was highly flawed and would probably not work well enough to make any difference.

Certainly Native American populations had been decimated by infectious diseases many times in the last few centuries and their numbers had been greatly reduced. But Amherst still had a terrible problem with hostile Native Americans. It was wishful thinking to hope that a new epidemic would be enough to end troubles with the Native Americans during his time in command. Especially since simply reversing Amherst's own polices toward the Native Americans and granting them what they wanted would have ended the trouble much faster.

But at least Amherst's evil and over optimistic plan contributed to reducing the numbers of the eastern tribes so that after a few years they were no longer any trouble, as Richard Butler and Francis Dade could testify. Correct?

https://en.wikipedia.org/wiki/Richard_Butler_(general)1

https://en.wikipedia.org/wiki/Francis_L._Dade2

Much later many plains Indian tribes were devastated by a smallpox epidemic in 1837. And after that the plains Indians tribes were never numerous enough to fight the US government, right? That is the reason why in the year 1890 such old soldiers as John Lawrence Grattan, William Judd Fetterman, and George Armstrong Custer said that the peaceful history of the plains since about 1840 had been caused by that great smallpox epidemic in 1837, and without it many brave soldiers would have died fighting the plains Indians. Correct?

https://en.wikipedia.org/wiki/John_Lawrence_Grattan3

https://en.wikipedia.org/wiki/William_J._Fetterman4

https://en.wikipedia.org/wiki/George_Armstrong_Custer5