14 Society for Experimental Biology and Medicine. 



pole, and not because true antitoxin had been formed. It was not 

 until 1904 that any attempt was made to determine the nature of 

 the electric charge carried by particles of toxin or antitoxin ; this 

 research, done in Von Behring's laboratory by Romer, gave only 

 negative results. Again in 1905, Biltz, Much, and Siebert, work- 

 ing in the same laboratory were unable to decide this question. 



The failure of these workers was due, we believe, to the disturb- 

 ing influence of the products of electrolysis. To eliminate this 

 factor we substituted for the U-shaped tube used in the above ex- 

 periments three beakers connected by agar-filled tubes, semicircular 

 in shape and about 20 cm. long and 1 cm. in diameter. The middle 

 beaker, into which both agar tubes dipped, contained the toxin or 

 antitoxin to be tested ; the end beakers held the platinum elec- 

 trodes surrounded by distilled water, which was changed every 

 half hour during the passage of the current. At the end of four 

 hours, the agar was removed from the tubes, chopped into fine 

 pieces and allowed to stand for one hour in distilled water. The 

 agar was then removed by filtering through gauze and the toxic or 

 antitoxic value of the fluid determined by tests on guinea pigs. 



The results of our experiments were decisive. Both toxin and 

 antitoxin particles were found to travel toward the cathode and 

 must therefore carry positive charges. This holds true when the 

 fluid tested is made either acid or alkaline in reaction. 



Since a true chemical reaction can take place only between ions 

 carrying charges of opposite sign, the fact that toxin and antitoxin 

 are both electropositive would indicate that the combination of 

 these two substances represents not a chemical union, but rather 

 the adsorption of one colloid by another. 



14 (157) 



Nuclein metabolism in a dog with an Eck fistula. 

 By J. E. SWEET and P. A. LEVENE. 



[From the Rockefeller Institute for Medical Research.'] 



A dog with an Eck fistula was maintained in nitrogenous 

 equilibrium on a diet consisting of cracker meal, plasmon and lard, 

 and the following chemical observations were made : 



1 . The output of uric acid was compared with that of a normal 

 dog. An increase in the output was noted. 



