"a Lavoisier or an Ampère"
Lavousier by Louis Jean Desire Delaistre
Public DomainLavousier by Louis Jean Desire Delaistre
Ampère
Public DomainAmpère

Antoine-Laurent de Lavoisier (1743-1794) is considered the 'father of modern chemistry'. He was a French noble, and was guillotined during the Revolution. 

André-Marie Ampère (1775-1836) was a French scientist who is regarded as one of the main discoverers of electromagnetism. The electricity measurement, the ampere (amp) is named after him.