What is not protected by a Patent?

Patent does not protect the following;

• discoveries of materials or substance already existing in nature;
• scientific theories or mathematical methods;
• plant or animal varieties or essentially biological processes for the production of such plant or animal varieties, other than microbiological processes;
• schemes, rules or methods, such as those for doing business, performing purely mental acts or playing games;
• methods of treatment for humans or animals, or diagnostic methods practised on humans or animals (but not products such as medicinal drugs for use in such methods)