Abderhalden has demonstrated that the parenteral introduction into the body of foreign protein or other material results in the appearance in the blood-serum of ferments capable of splitting these foreign substances into bodies which are less disharmonious with the organism. He has shown that these ferments are produced only by the presence in the blood of the corresponding material and that they seem to be specific; that is to say, that they are capable of splitting only the one particular variety of protein, or other substance, the injection of which resulted in their formation.
The dialysis method, by which proteolytic ferments may be detected, recommended by Abderhalden, consists essentially of two parts. First, about 0.5 gm. of sterile protein (which must be free from substances which react with ninhydrin) is placed with 1.0 to 1.5 c.c. of the sterile blood-serum under test, free from hemoglobin and blood-cells, in a