A NEW DIPHTHERIA ANTITOXIN

To the Editor:—  Your attention is called to an editorial comment entitled "A New Diphtheria Antitoxin" in The Journal, July 22, page 326.This comment discusses results obtained by Pope by means of peptic digestion of diphtheria antitoxic serum and does not give credit to Parfentjev, who first published the description of a successful method of refining diphtheria antitoxin using peptic digestion.A recent routine batch of diphtheria antitoxin processed by Parfentjev's peptic digest method contained at least 9,000 units per cubic centimeter and approximately 50,000 units per gram of protein. The potency referred to by Pope was 27,000 units per gram of protein.The antitoxin discussed by Pope has many of the same desirable characteristics as that processed by Parfentjev, because Pope used a method of carefully controlled peptic digestion similar to that previously described by Parfentjev. Antitoxin prepared by the Parfentjev method had been available as "Diphtheria Antitoxin