Note 1 — I. ITS NATURE.
Reading edition
According to Drs. Playfair and Lankester:
Teacontains3per cent.theine.
Coffee"1¾"caffeine.
Cocoa"2"theobromine.
Probably the proportion of caffeine in coffee would be more correctly stated as 1¼ per cent. Theine and caffeine are identical, but theobromine (C7H8N4O2) differs from both in the greater proportion of nitrogen which it contains.