In 1904, Ganghofer and Langer1 carried out some experiments on animals to test the permeability of the intestinal wall to foreign albumin. Their examinations consisted of precipitin reactions on the blood of new-born animals. They found that in young dogs or other animals previous to the sixth day of life, the precipitin reactions to foreign albumin were positive although the quantity of albumin consumed was very small. Their experiments were carried out on dogs, cats, rabbits and kids.
In 1913, Lust2 attempted to determine the presence of egg white in the urine of infants. For this purpose he used precipitin serum, which gave the reaction in dilution of 1: 100,000; oftentimes of 1: 1,000,000. He used egg albumin because it was much easier to recognize by the precipitin reaction. In his first series of ten infants suffering from various types of nutritional disturbances, he found that while the