In the life of Gay-Lussac the Revolutionary period (or more precisely the period after 1795) was the time when he received his basic scientific education. During the succeeding period of the Consulate Gay-Lussac was a research assistant to Berthollet, while the ten years of the Empire (1804–14) were for him a period of intensive scientific research. By the Restoration of 1815 Gay-Lussac had established an international reputation for himself. A French ‘Who's Who’ published in 1817 described him as ‘one of the most distinguished physicist-chemists of the capital’. He was now a part of the establishment. He came to replace Berthollet all the more naturally as his master had taken the eclipse of Napoleon as a time to withdraw from the public scene. Although Gay-Lussac had benefited indirectly through Berthollet by Napoleonic patronage he had never been formally associated with the imperial regime. Thus he could serve the restored Bourbon monarchy with a clear conscience, although perhaps not without a tinge of regret for old times. It was under the constitutional monarchy of Louis Philippe that Gay-Lussac reached his peak of power and influence.