626 



Journal of Agricultural Research voi. xiii, no. 



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

 disease of tobacco — Continued 



CARBOLIC-ACID SOLUTIONS AND PHENOco SOLUTIONS — Continued • 



ACETONE 



Virus in 10 per cent acetone . 



Virus i n 20 per cent acetone . 

 Virus in 30 per cent acetone. 

 Vi rus i n 40 per cent acetone . 

 Virus in 50 per cent acetone. 

 Tap water only (control) 



Oct. 6, 19x5 



.do. 

 .do. 

 .do. 

 .do. 

 .do. 



Dec. 22, 191S (77 

 days later). 



do 



do 



do 



do 



do 



10 Connecticut 

 Broadleaf. 



do 



do 



do 



do 



do 



9 plants mosaic. 



4 plants mosaic, 

 9 plants mosaic. 

 8 plants mosaic. 

 All healthy. 

 Do. 



The cresols are relatively more powerful germicides than carbolic acid. 

 Behring * has shown that for certain vegetative forms cresol may have 

 4 times and creolin lo times the germicidal power of carbolic acid. The 

 relative differences in the germicidal action of carbolic acid, cresol, and 

 creolin are not apparent in their effects upon the infectiye principle of 

 the mosaic disease of tobacco under the conditions of the writer's 

 experiments. 



In its germicidal action carbolic acid is supposed to act as a molecule, 

 and not by ionization; and the addition of salt greatly increases its 

 germicidal powers. In the time during which it has been allowed to act 

 in the above experiments, there appears to be no appreciable difference 



1 Behring, V. bEkampfung dbr inpbctionskrankheiten. ... 251 p. Leipzig, 1894. 



