44 



lows : a hole was made with a stick in the soil reaching nearly to 

 the bottom of the bed, or pot if such happened to be used, into this 

 was inserted a funnel to catch the liquid and convey it to the bottom 

 of the hole, after which the funnel was removed and the top of the 

 hole was stopped up with earth. The fumes from the very volatile 

 liquid soon permeate the soil and in this way many worms are killed. 

 It was not possible, however, to apply much of this solution to 

 pots containing cucumber plants, as we found that they were invaria- 

 bly injured even when as small a quantity as 15 drops were used, 

 although in the open soil it can be employed with much less injury 

 to the plants. Commercial Ammonia and Ammonia water from gas 

 works were usually applied in the same way as was the Carbon bisul- 

 fid, although neither of them at the concentration used caused any 

 injuries to cucumber plants. 



From the experiments with solutions we may draw the following 

 deductions : — 



There are many solutions capable of killing a certain percentage 

 of adult worms that can be applied to the soil either before or 

 after planting without injuring the plant. The strength and the 

 amount of the solution necessary to kill the adult worm in the soil 

 is considerably greater than that necessary to apply when the worm 

 is isolated. This is due to the difficulty in getting the solution to 

 come in contact with each particle of matter m and around which 

 the nematodes thrive. None of the solutions named above are 

 capable of killing the eggs of the nematode in the soil, and unless 

 this is accomplished the treatment is of no account. 



Sterilizing or Heating the Soil the most Effectual and Practical Method 

 of Exterminating Nematodes in the Greenhouse. 



Our experiments in heating the soil by means of steam for the 

 control of nematodes have been carried on for three years. At the 

 outset we did not happen to know of any practical method of heating 

 soil with steam — neither did we consider it wise to experiment too 

 extensively along this line until we had obtained more knowledge 

 of the efficiency of chemicals upon nematodes. Subsequently, how- 

 ever, we learned of some investigations being made by B. T. Gallo- 

 way' of the U. S. Dept. of Vegetable Pathology on the effects of 

 heating soil by steam for the purpose of ridding it of violet 



I For description see American Gardening Vol. XVIII, 1S97 P- '27. 



