the administration of certain foods; 2) Development of analytical capabilities to identify classes of nutrients in foods; 3) Experimental induction of dietary diseases in animals; and 4) Administration of synthetic diets to discover essential nutritional factors. Most of the history of vitamins is linked to efforts to find cures for human diseases such as night blindness, xeropthalmia, scurvy, beriberi, rickets and pellagra. Experiments with animals including rats, mice, chickens, pigeons, guinea pigs and dogs contributed greatly to the advances made in vitamin research between 1900 and the 1930s.