July 24.1916 Properties of the Virus of Mosaic Disease 655 



TREATMENT OF THE VIRUS WITH HYDROGEN PEROXID 



Experiments have shown that certain quantities of hydrogen peroxid 

 (U. S. P., 3.10 per cent) may be added to the virus of the mosaic disease 

 without destroying its infectious properties. By treating the virus with 

 different quantities of hydrogen peroxid, it is possible to find concentra- 

 tions which destroy the peroxidase and at the same time leave little or 

 no free hydrogen peroxid in the solution. Schonbein (19, p. 474) and 

 likewise Bach and Chodat (2, p. 603) have observed that while peroxidase 

 activates small amounts of hydrogen peroxid, large amounts of hydrogen 

 peroxid destroy the peroxidase (Table V). 



These results show that hydrogen peroxid may destroy the peroxidase 

 in the virus without destroying its infectious properties. Although such 

 solutions no longer give peroxidase reactions, they may retain their 

 infectious properties for a long time. If the quantity of hydrogen per- 

 oxid is considerably increased beyond that concentration which is suffi- 

 cient to destroy all the peroxidase, hydrogen peroxid remains in excess 

 in the solution and the virus sooner or later loses its property of infection. 



Chodat (6, p. 642-645) and other investigators have shown the definite 

 relations existing between peroxidase, hydrogen peroxid, and the oxida- 

 tion products. It has been shown that for constant quantities of per- 

 oxidase, the oxidation products increase directly with the amount of 

 hydrogen peroxid present, within certain limits, until all the peroxidase 

 is combined or used up. 



The quantity of hydrogen peroxid required to destroy the peroxidase 

 varies greatly, depending upon the composition of the virus. If the 

 virus evolves little or no oxygen upon the addition of hydrogen peroxid, 

 a very small quantity of this reagent destroys the peroxidase. 



From Table V it will be seen that a very small quantity of hydrogen 

 peroxid (3.1 per cent, U. S. P.) destroyed the peroxidase in virus X 20 . 

 As the quantities of hydrogen peroxid were increased, a point was reached 

 where the excess was sufficient to kill the infective principle of the virus. 

 If a considerable excess is present in solutions of virus for any length 

 of time, such solutions lose their green or brown color and become pale 

 or almost as clear as water in some instances. With the addition of 2 

 c. c. of hydrogen peroxid to 23 c. c. of virus X 20 , a small excess of hydro- 

 gen peroxid was noticeable for several days, but this later disappeared. 

 It has been observed by Bach and Chodat (3, p. 173) that if a mixture 

 of peroxidase and hydrogen peroxid is allowed to stand for some time, 

 both disappear from the solution by mutual interaction and destruction. 



