'susceptible of' vs 'susceptible to"

What are their similarities and differences? The definitions on http://www.oxfordlearnersdictionaries.com/definition/english/susceptible look similar: for example, A is 'influenced or affected' by B, if and only if, "A allows B". So same meaning?

I see that the examples containing + of connotes negativity, but does this imply anything (more profound)?

Solution 1:

There are two fundamentally different uses of susceptible. For those who distinguish by preposition, the difference is as follows:

1. Susceptible of roughly means capable of, admitting. Something can be susceptible of proof, of a solution, of division, of observation, of being considered, etc.
2. Susceptible to roughly means able to be affected by. Something (or someone) can be susceptible to light, to disease, to infection, to poison, to attack, etc.

I said fundamentally different, but there is some overlap. E.g., a cake admits division if and only if it can be affected by a division. An organism is of course more likely to be affected by a poison if it admits it into itself. Such cases can be a vehicle for language change, as the border between what is acceptable and what isn't moves gradually.

The following is the result of my research with Google's ngram viewer.

Around 1800, of was almost universally used for both senses. However, there was already a small number of uses of to -- invariably in sense 2.

In the course of the 19th century, to became used more and more for sense 2, and in the end it was more common in that case. For light the tipping point was in the middle of the century, for disease around 1877, for infection around 1885.

There is a slow trend, starting around 1900, for to to take over sense 1 as well. With some words, of is still more popular than to: for application by a factor of 10, for proof by a factor of 2, for division by a smaller margin. With others, to seems to have won already, as it is now more popular than of: for observation by factor of 4 (more popular since around 1950), for a solution by a factor of 1.5 (more popular since 1960s/70s).

Conclusion: It's still best to distinguish senses 1 and 2 as described above. If you don't want to, follow the advice of the dictionaries that will appear a hundred years from now and use only to.

Solution 2:

There is no difference.

Google Ngrams shows that "susceptible to" has gradually been replacing "susceptible of" over the last 200 years, and I suspect that in another 50 years "susceptible of" will probably be gone. If there were a difference, "susceptible of" couldn't have gone from being 98% of the uses in 1800 to being 8% of the uses today. British and American English don't seem to differ much in this respect.