July 24, 1916 Properties of the Virus of Mosaic Disease 



663 



acid reaction. On this date the greater portion of the clear super- 

 natant solution was carefully siphoned off. After pouring off as much 

 of the remaining supernatant solution as possible, the semiliquid pre- 

 cipitate, or sludge, was bottled. The clear supernatant solution, as well 

 as the sludge, gave intense peroxidase reactions. 



As seen from the equation, the treatment of the original virus solution 

 involves the formation of 2.7 gm. of the soluble salt (sodium sulphate) 

 or 1 part in 370 of solution. 



As a control to this there was prepared on December 1 a solution of 

 virus of the same dilution as the original, containing 6 gm. of sodium 

 sulphate per 1,000 c. c. of solution, or approximately 1 part of sodium 

 sulphate in 303 parts of solution. It will be noted that this concentra- 

 tion is somewhat higher than that obtained in the reaction to produce 

 1 gm. of aluminum hydroxid. 



The preparation of the nickel-sulphate solution, involving the forma- 

 tion of 2 gm. of nickel hydroxid, was carried out in the same manner as 

 for the aluminum hydroxid. The results of inoculations made with the 

 supernatant solutions and precipitates of aluminum hydroxid and nickel 

 hydroxid are given in Table X. 



Table X. — Effect of aluminum hydroxid and nickel hydroxid upon the infectivity oj 

 mosaic virus, 10 plants having been used in each test. Material prepared on December 

 I, 1915 



Material tested. 



Inoculations made on December 16, 1915: 



Semifluid aluminum hydroxid precipitate. 



Do. 



Supernatant solution from above precipitate 



Semifluid nickel hydroxid precipitate 



Supernatant solution from above precipitate 



Sodium-sulphate-virus solution (1 part sodium sulphate in 

 303 parts of solution). 



Do 



Original virus X 23 used in above tests, untreated 



Tap water (control) 



Inoculations made with above material on January 18, 1916: 

 Semifluid aluminum hydroxid precipitate 



Supernatant solution from above precipitate 



Semifluid nickel hydroxid precipitate 



Supernatant solution from above precipitate 



Original virus X 23 used in above tests, untreated . 

 Tap water (control) 



Enzymic reaction 

 after treatment. 



Intense 



Dec. ij 

 ...do.. 

 ...do.. 



do.. 



....do.. 

 ....do.. 



peroxidase, 

 1915- 



.do. 

 .do. 



Intense peroxidase, 

 Jan. 17, 1916. 



do 



do 



do 



do 



Result of inocu- 

 lating plants. 



1 mosaic. 



3 mosaic. 

 All healthy. 



Do. 



Do. 



10 mosaic. 



Do. 



4 mosaic. 

 All healthy. 



6 mosaic. 



All healthy. 

 1 mosaic. 

 All healthy. 

 10 mosaic. 

 All healthy. 



From the results of Table X it is quite evident that the infective 

 principle of the virus was carried down with the aluminum hydroxid 

 precipitate, leaving the supernatant solution free from infectious prop- 

 erties. Since the treatment with nickel sulphate appears to have 

 destroyed the virus entirely, it is possible that nickel salts are more 

 toxic to the infective principle than the salts of aluminum. 



