I it; I'm!. M. ' . l'.<;tT. On a Ji,tn-inl 



course of three or four clays nearly the whole contents had become 

 rotten. 



The next important step was to separate the bacteria from their 

 products. The contents of the flask were turned out and pressed 

 through a cloth into a glass cylinder to remove the coarser portions, 

 the turbid liquid was then filtered, and afterwards diluted with four to 

 five times its bulk of alcohol. Almost immediately on addition of the 

 alcohol a cloudy precipitate formed, and, at the end of twenty-four 

 hours, a copious flocculent precipitate was deposited. After filtration 

 the precipitate was washed with absolute alcohol, dried, carefully 

 collected, and then digested with distilled water for about three hours. 

 The solution was then passed through a Pasteur-Chamberland filter 

 fixed in a Maassen's bacteria filter. In this manner a clear, pale, straw- 

 coloured liquid was obtained free from bacteria. The liquid when 

 drawn into sterile test-tubes remained clear for any length of time, but 

 when exposed to the air it soon became turbid. A series of ten such 

 sterile test-tubes was prepared, five of which were held over a Bunsen 

 burner, and the fluid allowed to boil ; the other fivQ were left without 

 any exposure to heat. Thin sections cut from sterile blocks of turnip, 

 by means of a razor steeped in boiling water, were taken off in sterile 

 water and quickly introduced both into the boiled and unboiled fluids. 

 The action of the unboiled fluid was very marked. Fig. 1 shows a 



Fig. 1. Group of cells from a section of turnip which has been exposed to the 

 action of the cjtnse for twenty-four hours. The cell-walls are swollen 

 and irregular in outline, and the cells are separating along the middle 

 lamella (Zeiss, E. oc. 2). 



section taken from one of these preparations after twenty-four hours' 

 exposure : the cell-wall is swollen and striated, and so much softened 

 that great difficulty was found in handling the section and removing 

 it to the slide ; it is well seen that the walls have quite lost their 





