French chemist in history linked to half of Europe (7)
I believe the answer is:
pasteur
'french chemist' is the definition.
(I've seen this before)
'history linked to half of europe' is the wordplay.
'history' becomes 'past' (I've seen this before).
'linked to' says to put letters next to each other.
'half of' means to take half the letters.
'europe' cut in half is 'eur'.
'past'+'eur'='PASTEUR'
'in' acts as a link.
(Other definitions for pasteur that I've seen before include "French scientist" , "French chemist and biologist, d. 1895" , "Louis --, French chemist and microbiologist" , "Famous bacteriologist" , "French chemist, 1822-95" .)