744 CHEMISTRY OF TOXIN AND ANTITOXIN 



cathode. If the velocity of this water-streaming were great enough in comparison to 

 the migration of the protein to the anode, the water would sweep the protein along 

 with it. Direct quantitative proof to substantiate this explanation is very difhcult to 

 obtain with an agar membrane 20 cm. thick through which varying amounts of 

 protein and electrolytes are being drawn. In the Field and Teague apparatus an 

 average of i cc. of water per hour is transported through the agar endosmotically 

 when water alone is electrolyzed. A micro-cataphoretic study' of the velocity of egg- 

 albumin particles, pH 7.2, showed that under a potential difference of 45 volts they 

 migrated at the rate of 8.1 ^t per second, or 29.1 mm. per hour. 



Indirect proof of this explanation is supplied by the fact that factors which effect 

 endosmotic streaming of the water also alter the amount of protein found in the 

 cathode arc. We concluded, therefore, that the protein which has been found in the 

 cathode portion of the agar in the Field and Teague apparatus when alkaline solutions 

 were electrolyzed has not migrated toward the negative pole by virtue of the positive 

 charge upon the protein, but has most probably been carried there by the endosmotic 

 flow of the water in contact with the agar.^ This conclusion has been further justified 

 by experiments now in progress in which it is found that antitoxin and toxin migrate 

 with protein to the anode in alkaline solution in a U-shaped cataphoresis apparatus. 

 Antitoxin migrates to the cathode in a solution of pH 4.6. Toxin is more sensitive to 

 acidification, losing its potency at a pH between 5.0 and 4.5. The results so far ob- 

 tained are in agreement with earlier work, which indicates that antitoxin, if not of 

 protein nature itself, is closely adherent to a protein of the plasma. 



CONCLUSION 



The reaction of toxin with antitoxin cannot be explained upon a chemical basis 

 because the reagents are not known chemical entities. As colloidal protein solutions, 

 or hydrophilic sols, their mutual neutralization can be explained as an adsorption re- 

 action. However, an explanation of the specificity of the union will most probably 

 await their definite chemical characterization as well as an advancement of our knowl- 

 edge of surface chemistry. 



A misinterpretation of the results obtained with their apparatus led Field and 

 Teague to assign a positive charge to toxin and antitoxin. In a U-shaped catapho- 

 resis tube, toxin and antitoxin migrate to the anode in alkaline solution. Antitoxin 

 migrates to the cathode in a solution with a pH of 4.6, and can therefore be said to 

 be an amphoteric colloid. 



'A simplified micro-cataphoresis cell was used. See I'alk, I. S., et al.: Am. J. Piih. Health, 17, 

 714. 1927. 



2 Stary, Z. {Ztschr. f. phys. Clieinie., 126, 173. 1927) has explained the anomalous migration 

 of oxygen and glucose in the Fiirth high-potential apparatus upon similar grounds. The "half-con- 

 ductors" which favor endosmotic streaming in this apparatus are porous clay or wet blotting paper. 

 See Glickhorn, J., Fiirth, R., and Bliih, O.: ibid., 123, 344. 1926. 



