Coffee contains, besides caffeine, such harmful things as pyridine, caffeol, tannic acid, and aromatic oils. Pyridine is a poison developed by roasting the coffee.
Coffee decreases one's efficiency. It hides, but does not relieve fatigue. Fatigue is produced quicker when coffee is used than when it is not used. Coffee weakens the mind's power of concentration and unsettles the nervous system. There is an inevitable depression in the coffee drinker, if he does not get his accustomed cup. Coffee excites and whips up the heart and increases blood pressure.
Coffee, says Tilden, is "a table beverage that has no excuse for its existence, except that the average human being abhors clean water, that mental vacuums do exist and can be turned to profit."
The caffeine of coffee is a stimulant (excitant) and all stimulants draw upon the body's reserves. Decaffeinized coffee is not decaffeinized and is not advisable even if it were. There are other poisons in coffee besides the caffeine. Kellogg says that there are nearly a dozen other of these coffee poisons.