[Vol. 



164 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



TABLE II 



DISINFECTION OF CANADA FIELD PEAS BY FORMALIN, MERCURIC BICHLORIDE, 



AND CHLORAZENE. FINAL OBSERVATIONS AFTER 96 HOURS, 26° C. 





Treatment 2 hours 



Treatment 1 hoi 



ur 



Disinfectant 



% Germi- 



% Contami- 



Condi- 



% Germi- 



% Contami- 



Condi- 





nation 



nation 



tion 



nation 



nation 



tion 



* .2% formalin 



77 



50 



Fair 



93 



10 



Good 



.2% formalin 



70 



66 



Poor 



83 



43 



Good 



* .l%HgCU 



16 







Injured 



24 







Injured 



.1% HgCl 2 



47 







Fair 



76 







Fair 



*4% chlorazene 







10 



Injured 







50 



Fair 



4% chlorazene 



16 



40 



Fair 



56 



13 



Fair 



*2% chlorazene 



33 



6 



Fair 



43 



6 



Good 



2% chlorazene 



40 



33 



Good 



63 



6 



Good 



*1% chlorazene 



86 



20 



Good 



80 



10 



Good 



1% chlorazene 



83 



30 



Good 



80 



30 



Good 



* In these cases the seed were soaked for 16 hours prior to treatment, while 

 in the other cases dry seed were treated. 



being 5, 20, and 60 minutes. After 60 hours practically every 

 seed was contaminated, so that the results are not tabulated. 



In table in are given further results with chlorinated lime 

 and potash. The intervals employed are too short for best 

 results, so that the percentage of contamination runs high. 

 Moreover, these experiments were made several months later 

 than those included in tables i-ii, and the seed were not so 

 fresh. It seems clear, however, that short treatments are not 

 satisfactory, and the value of longer intervals is particularly 

 emphasized later. 



A further extensive test of chlorinated lime, employing 

 intervals of treatment up to 3 hours and using the freshest 

 seed available, was made with the special view of determining 

 the effect of the agent on the germination of the seed. The 

 results are given in detail in table iv. The effectiveness of 



this disinfectant with corn and cucumber is clear. The per- 

 centage of germination with peas and radish is relatively low. 

 This lot of radish seed proved difficult to sterilize, and the 

 presence of a resistant organism spreading rapidly over the 

 surface of the dishes tended to reduce the percentage of ger- 

 mination. 



The test of sodium hypochlorite was made by preparing the 



Heated 



solid 



