EEMEBIAL MEASUKES. 59 
THE USE OF POTASSIUM CYANID AGAINST THE WIREWORMS. 
Potassium cyanid was one of the first remedies tested for the wire- 
worms, because it has the properties both of an excellent deterrent 
and a deadly poison. Used as a deterrent, the seeds were treated in 
two different ways. In the first the cyanid was used as a solid and 
drilled in with the seed. This method affords excellent protection 
to the seed, but the drawbacks connected with it have thus far made 
it impracticable. The cyanid burns the seed wherever it comes in 
contact with it, and when germination begins, it burns the tender 
roots. Another argument against its use for this crop is its cost. In 
the second method of seed protection the seeds were soaked over- 
night in a solution of cyanid in water, dried, and planted. In this 
method it was also quite effective as a deterrent, but unfortunately 
its effects on the roots were such that it could not be used. At the 
present time it seems very doubtful if the cyanid can be used in such 
a strength that it wiU keep away the wire worms and at the same 
time not harm the plants. This point is going to be tested further. 
While these experiments were being carried on it was noted that 
in some of the cages most or aU of the wireworms had been killed. 
These larvae had the appearance of having been kiUed by a fungus, 
but as their bodies were not filled with the fungus it w^as apparent 
that they had been killed in some other way. It was thought that 
perhaps they had been killed by the fumes of the cyanid, and later 
experiments seemed to bear out this point. With this in Adew, many 
experiments were carried on in an attempt to discover some good 
method for the application of the cyanid. From these, two plans 
were selected for final trials, one in which the cyanid was used as a 
solid, and the other in which it was used as a liquid. The results are 
given below. 
According to the first plan the cyanid was drilled into the ground 
much after the method used for fertihzers. This plan was finally 
given up, as the cyanid was not distributed evenly through the soil, 
and therefore had to be applied more heavily than was necessary in 
order to be effective. As the cyanid is very destructive to plant 
growth it is readily seen that it would have to be used as sparingly 
as possible. 
The method of using the liquid consisted in making a solution of 
the cyanid in water and applying it evenly over the land. This 
could then be made to permeate the soil to any depth by irrigation. 
By this method the cyanid is used sparingly, as it is evenly applied. 
Unfortunately it has been impossible to try this remedy thoroughly, 
up to the present time. In all the experiments where this method 
was employed its killing power was very good. To test it further, 
it was applied in a cage containing beets, with the result that both 
