Tobacco in general has never been patented, because
1. It is a plant, not a product
2. It was discovered a LONG time ago, so that even if it could have been patented, the patents would have expired centuries ago.
I don't know. But the way to find out is www.USPTO.gov. The US Patent and Trademark Office. They allow searches by many criteria. It will take just a little work, but once you know how to search on USPTO, your power will increase.
Dupont
There are literally hundreds of patents for carburetors all over the world, and you would need to look in the patent files of the country of interest, and in the specific category and subcategory related to the particular invention that applied to the carburetor.
The patent was issued to Maurice A. McLean and Stephon D. Brown.
stockholders
Since Dupont invented it, one would suppose Dupont once owned the patent for it. However, it would have expired or lapsed many years ago because they started using it in the early 1930s. So, in other words, there is no patent for R-11.
The patent for Viagra in in the United States is owned by the company Pfizer. Pfizer is a pharmaceutical business that has continuously and exclusively maintained the patent for the Viagra brand name and the drug Sildenafil.
Jesus invented this amazing shredded gold!
There is only one way to get a patent: apply to the Patent Office in your country.
They wouldn't "steal" your patent, in the sense that you would still own the patent, but they could certainly use your patent to make, use and sell your invention in any other country where you failed to patent it.
MDMA is not currently protected by a patent. The closest thing is Alexander Shulgin's 1959 patent on "4 alkyl dialkoxy N methyl phenethylamines and their pharamcologically acceptible salts," which has expired.
had to have been the inventor George Beauchamp in 1931 as he owns the patent for electric Guitars and single coil pickups.