624 



Journal of Agricultural Research 



Vol. XIII, No. 12 



Table I. — Effects of various chemicals on the infectivity of the virus of the mosaic 

 disease of tobacco — Continued 



POTASSIUM PERMANGANATE 



ZINC CHLORID 



I gm. to 50 c. c. of virus solution. . 



I gm. to 100 c. c. of virus solution. 

 I gm. to 200 c. c. of virus solution. 

 Tap water only (control) 



I gm. to 100 c. c. of virus solution. . 



I gm. to 200 c. c. of virus solution. . 

 I gm. to 400 c. c. of virus solution. . 

 I gm. to 600 c. c. of virus solution. . 

 I gm. to 800 c. c. of virus solution. . 

 I gm. to 1 .000 c. c. of virus solution 



Virus without addition 



Tap water only (control) 



Oct. 12,1915 



.do. 

 do. 

 .do. 



Feb. 21,1916 



.do. 



.do. 

 .do. 

 .do. 

 .do. 



.do. 



Dec. 29. 1915 (78 

 days later). 



....do 



....do 



....do 



Mar. 30, 1916 (36 

 days later), 

 do 



.do. 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 



10 Connecticut 

 Broadleaf. 



....do 



....do 



....do 



.do.... 



.do. 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 



All healthy. 



Do. 



8 plants mosaic. 

 All healthy. 



Do. 



3 plants mosaic. 



7 plants mosaic. 



6 plants mosaic. 



8 plants mosaic. 



7 plants mosaic. 



8 plants mosaic. 

 All healthy. 



COPPER SULPHATE 



I gm. to 25 c. c. of virus solution. 



1 gm. to 50 c. c. of virus solution. . . . 

 I gm. to 100 c. c. of virus solution. . . 

 I gm. to 200 c. c. of virus solution. . . 

 I gm. to 500 c. c. of virus solution. . . 

 I gm. to 1,000 c. c. of virus solution. . 



Virus without addition 



Tap water only and weak solution 

 copper sulphate (control). 



I gm. to 100 c. c. of virus solution. . . 



I gm. to 200 r. c. of virus solution. . . 

 I gm. to 400 c. c. of virus solution. . . 

 I gm. to 600 c. c. of virus solution. . 

 I gm. to 800 c. c. of virus solution. . 

 I gm. to 1,000 c. c. of virus solution 

 I gm. to 1,200 c. c. of virus solution 

 I gm. to 1,500 c. c. of virus solution 



Virus without addition 



Tap water only (control) 



Apr. 28, 1914 



.do. 

 .do. 

 .do. 

 .do. 

 .do. 



Nov. 17, 1915 I) 



.do. 

 .do. 

 .do. 

 .do 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 



May 7, 1914 (9 

 days later). 



do 



do 



do 



do 



do 



do 



do 



Dec. 19, 1915 (32 

 days later). 



do 



do 



do 



.do. 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 



10 Connecticut 

 Broadleaf. 



....do 



....do 



....do 



....do 



....do 



....do 



....do 



.do. 



.do. 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 



All healthy. 



Do. 



Do. 



Do. 



Do. 

 8 plants mosaic. 



Do. 

 All healthy. 



r plant mosaic. 



5 plants mosaic. 



7 plants mosaic. 



9 plants mosaic. 



10 plants mosaic 



8 plants mosaic. 



7 plants mosaic. 

 10 plants mosaic. 



8 plants mosaic. 

 All healthy. 



CARBOLIC ACID 



I gm. to 100 c. c. of virus solution. . , 



I gm. to 200 c. c. of virus solution. . 

 I gm. to 400 c. c. of virus solution. . 

 I gm. to 600 c. c. of virus solution. . 

 I gm. to 800 c. c. of virus solution. . 

 I gm. to 1. 000 c. c. of virus solution 

 I gm. to 1,500 c. c. of virus solution 



Virus without addition 



Tap water only (control) 



Nov. 16, igrs 6 



.do. 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 

 do. 

 .do. 



Dec. 18, 191S (32 



days later). 

 do 



.do. 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 

 .do. 



10 Connecticut. 



.do 

 .do 

 .do 

 .do 

 .do 

 .do 

 .do 

 .do 



10 plants mosaic. 



Do. 



Do. 



Do. 



Do. 



Do. 



Do. 

 9 plants mosaic. 

 All healthy. 



a Virus unfiltered. 



b Virus filtered clear through filter paper before solutions were made. 



