•230 The Celenj-Rot Bacillus 



precipitation which occurs interferes with its germicidal properties; 

 at the end of an hour the maj ority of the bacilli must have been killed, 

 for a 2 mm. loopful contained no living forms, as shown by the absence 

 of any growth in the sub-inoculated tube. The few surviving rods, 

 developing after the precipitation of the reagent, rendered succeeding 

 inoculations capable of producing turbidity in the culture medium. 



Copper sulphate when employed in the form of Bordeaux mixture 

 is very efficient in controlling "Celery Leaf- blight" (35) and its success 

 as a germicide in celery extract suggests that the spraying operations 

 against the "blight" might tend to reduce the chances of infection 

 by the soft-rot organism, though it is to be noted that in the Bordeaux 

 mixture itself there is no free copper sulphate. 



The other four reagents could be used as disinfectants in those 

 places where celery or roots (carrots, turnips, etc.) are to be stored, 

 if the soft-rot had been observed on vegetables stored there previously. 

 Formaldehyde, though a powerful disinfectant, is not to be recommended 

 however for use in this manuer owing to the irritation produced on 

 the mucous membrane by the gas when it passes out of solution. 



In order to obtain confirmation of the previous results with copper 

 sulphate and permanganate of potash the experiment with these sub- 

 stances was repeated and lower concentrations were also tried for 

 comparison, with the results here shown. 



Transfer at end of 



1 hour 4 hours 24 hours 3 days 



Copper sulphate 01 - - - - 



0-05 _ _ _ _ 



001 _ _ _ _ 



Potassium permanganate 0-1 - - - -I- 



0-05 _ _ _ + 



001 - + + - 



On this occasion the agitation of the tubes immediately after adding 

 the reagent was more thorough than in the previous experiment and 

 this probably accounts for the more efficient action of the permanganate. 



A further trial was made with potassium permanganate at a con- 

 centration of 0-01 % using the celery extract at half the original strength ; 

 there was still some precipitation but the action was more effective. 

 The tube was well shaken on adding the reagent and again immediately 

 before each sub-inoculation. These sub-inoculations as before were 

 made after 1 hour, 1 hours, 24 hours, and 3 days respectively, two 

 tubes being inoculated at the end of each period : — 



