Honor de Balzac is said to have consumed the equivalent of 50 cups of coffee a day at his peak. He did not drink coffee, though -- he pulverized coffee beans into a fine dust and ingested the dry powder on an empty stomach. He described the approach as horrible, rather brutal, to be tried only by men of excessive vigor. He documented the effects of the process in his 1839 essay "Trait des Excitants Modernes" ("Treatise on Modern Stimulants"): "Sparks shoot all the way up to the brain while ideas quick-march into motion like battalions of a grand army to its legendary fighting ground, and the battle rages."
Balzac's novels and plays endure, but modern science is challenging his view of caffeine causing ideas to "quick-march into motion." While caffeine has numerous benefits, it appears that the drug may undermine creativity more than it stimulates it.