I had a bottle of nicotine nitrate solution, to be used in a spray emulsion. In the past, nicotine was a commercial pesticide.
I used a commercial nicotine-based pesticide in my home garden 25 years ago so this is nothing new. As I recall it wasn't very effective.
Exactly. It is hardly a discovery to determine that nicotine is an effective herbicide.
That characteristic is part of the cause of “smoker’s cough” — over the years of smoking, the nicotine kills the ciliated epithelium in the lungs, and the smoker’s lung cannot naturally expel junk and dirt — so they cough and hack it out.