Since the work of Minot and Murphy,1 in 1926, the presence of a substance in liver, effective in producing remissions in pernicious anemia, has been repeatedly demonstrated. More recently, Castle2 has shown that the digestion of beef in normal gastric juice leads to the formation of an effective substance, possibly identical with that present in liver. The nature of the substance in beef responsible for this reaction is not definitely known but it is conceivable that the same substance may also be present in liver, in addition to the effective agent already there. If so, the digestion of liver with normal gastric juice should give a material more potent in pernicious anemia than whole liver.
Walden and Clowes3 have succeeded in increasing the potency of liver by mixing it with stomach tissue. The details of the method have not been published, but they mention that they had