soda, has to be used to dissolve it. When large amounts 

 of the solution are required, washing soda will be the 

 cheaper, but for small quantities of solution, caustic 

 soda will possibly be found the handiest. 



When preparing the solution, whether caustic soda 

 or washing soda is used, first dissolve the soda in a con- 

 venient amount of water, using heat, if desirable, to 

 assist and hasten it; then slowly add the arsenic, pre- 

 viously made into a thin paste (as the housewife treats 

 her cornflour), stirring all the time; place on a strong 

 fire, and after it has come to the boil, allow it to remain 

 boiling for at least half an hour ; stir from time to time, 

 and be careful to stand on the side away from the 

 fumes, as, being poisonous, they are apt to cause sick- 

 ness. When the arsenic is thoroughly dissolved, the 

 solution may be made up to the required bulk by adding 

 the remainder of the water, either hot or cold. 



A useful strength for quick and effective work in all 

 kinds of timber is as follows: 

 Arsenic, 1 Ib. 



Washing soda, 1 Ib. or caustic soda y* Ib. 

 Water, 4 gallons. 

 Whiting, y 2 Ib. 



The addition of this whiting is merely that it may serve 

 as an indicator on trees treated, as it turns white on 

 slightly drying, making it quite certain what trees 

 have been operated on. 



The time to carry out the work of poisoning is when 

 the tree is dormant, that is in the winter months. 



Trees can be killed by arsenic or ringbarking at prac- 

 tically any time of the year, but to prevent suckering 



19 



