228 The Celery-Rot Bacillus 



The medium used consisted of the following: — 



Distilled water 1000 c.c. 



Ammonium nitrate 10-0 gm. 



Dipotassium phosphate 2-5 ,, 



Magnesium sulphate 0-4 ,, 



Sodium chloride 2-5 „ 



Sodium asparaginate 3-0 ,, 



Saccharose 10-0 ,, 



To maintain a constant known temperature the tubes were placed 

 in a thermostat at 25° C. 



The various antiseptics were prepared and added as before; the 

 lysol as used on the previous occasions was not available so a "Lysol 

 Substitute" was used in its place. Control tubes (uninoculated) in 

 which the antiseptics were added at the lowest concentration used 

 in the inoculation remained clear throughout the experiment (white 

 flocculi appeared in the tube containing lysol substitute but the liquid 

 in which they floated remained clear). The results showed no wide 

 divergence from those obtained when bouillon was the medium used. 



Copper sulphate and permanganate of potash as before were in- 

 efficient in concentrations up to 0-1 %. At this strength the perman- 

 ganate was thrown out of solution by the formation of an insoluble 

 precipitate; the copper sulphate however remained in solution so 

 higher concentrations were used, e.g. 0*15 % and 0-2 %, but in these 

 crystals of a copper compound made their appearance, the liquid 

 became turbid and motile rods were present. 



Formaldehyde and chloroform appear to be a little more effective 

 in preventing growth in the synthetic medium than in bouillon. 



In the tubes containing alcohol there was the same sequence in 

 the appearance of visible signs of growth but the periods intervening 

 between the commencement of development in tubes of 2 %, 4 % and 

 6 % were considerably reduced as was to be expected by reason of the 

 higher temperature. 



Benzoic and salicylic acids were prepared in saturated solutions 

 in the medium at the temperature of the thermostat and diluted with 

 the medium in the proportions required. Under these conditions 

 salicylic acid as a one-tenth saturated solution prevented growth while 

 a one-fifth saturated solution was necessary with benzoic acid. 



