Sadly, it's not online that I know of. Here are pictures of the text:

https://www.dropbox.com/s/5sa0m8l9u6211y4/2019-03-26%2019.21... https://www.dropbox.com/s/dwbh9i7a4dcx84g/2019-03-26%2019.22...

The book [https://www.amazon.com/Garners-Modern-English-Usage-Garner/d...] is worth owning.