632 



Journal of Agricultural Research voi. xiii, no. 12 



Table II. — Effect of various concentrations of alcohol upon the infectivity of the virtis 

 of the mosaic disease — Continued 



VIRUS I (preserved in 40-75 PER CENT ALCOHOL ON FEBRUARY 12, I915) 



The results of inoculations vnth alcoholic solutions of virus A show 

 that the virus of mosaic was not affected by 25 per cent alcohol. Its 

 viability, or at least its power to infect, appeared to be unchanged 199 

 days later. The 50 per cent alcohol solutions were infective 35 to 36 

 days after preparation, although it is evident that the power to infect 

 had fallen considerably below that of the original virus. Inoculations 

 made with these strengths 40 to 41 days after preparation indicate that 

 the virus in 50 per cent alcohol had become innocuous to healthy plants. 



The tests with alcoholic solutions of virus C show very clearly that the 

 virus of mosaic can not long retain its infectious properties in alcohol 

 stronger than 50 to 55 per cent. Five days after preparation all solu- 

 tions containing 55 per cent or more of alcohol became innocuous. The 

 virus gives evidence of lessening virulence in the 50 per cent alcoholic 

 solution. The power to produce infection appears to have been com- 

 pletely lost by the 50 per cent solution 2 1 days after preparation. Tests 

 of these solutions 140 days later indicate that the 45 per cent solution 

 was still infectious to healthy plants. 



Practically the same results are shown with alcoholic solutions of virus 

 F. All solutions up to 50 per cent were infective 6 days after prepara- 

 tion. As in preceding tests, the 50 per cent solution again gave evidence 

 of decrease in the power to produce mosaic. 



Tests with virus D indicate that the virus of the mosaic disease pre- 

 served in 80 per cent alcohol became innocuous in less than half an hour. 



