OVERSEAS STUDENTS' GUIDE TO ENGLISH STUDIES (LONGMANS,1966) says that we discover a new medicine rather than invent a new medicine.
But we often see 'develop a new medicine'. How do native English speakers use these three verbs for 'a new medicine'? Thanks.
Generally, you discover something that is natural, something that already exists.
You invent something new, something that has to be made, manufactured, following a series of steps, procedures.
Develop is similar to invent, but it stresses that it's a complicated process, with experimentation, trial-and-error.
Penicillin was discovered by accident, when a scientist left a dish uncovered.
The transistor was invented to take the place of vacuum tubes.
Scientists are working to develop a vaccine for AIDS.
English speakers are sometimes careless about these distincitions--I've heard electricity referred to as an "invention." Electricity was a discovery, not an invention. The electric light bulb was an invention. The system for distributing electricity across continents was developed.
wishing you success