Louis Pasteur had been working to find a vaccine that would cure cholera in chickens. His lab assistant gave an older, weaker strain of the disease to the birds. When these birds did not die Pasteur began to rethink his ideas a came up with our current method of administering vaccinations.
A linguist studies language in a scientific way; so not just a certain language like Spanish, Mandarin or such, but how a language is written, communicated, it's forms, etc.
