:300 Winter Cover Washes 



Practically both (5) and (6) were too thick to put through a spraying 

 machine. As alum gave disappointing results, aluminium sulphate 

 was substituted to avoid the presence of the soluble potassium sulphate. 

 The following mixtures were tried: 



Iron sulphate Water 

 -^ 10 



10 



No. (2) gave too thin a coat while No. (1) appeared satisfactory. 

 The better mixtures of those tried on the upright posts were then 

 sprayed on to trees with the results included in the table below: 



1 i — 



(6) U 



(7) \\ — — — — — -h '. 



The weather in the three weeks of trial included rain, snow, frost 

 and wind. 



Of these mixtures by far the best was (2). The amount of whiting 

 was decreased from eight to six as the larger amount was difficult to 

 incorporate with the water required by the formula. The aluminium 

 sulphate and the alum mixture were disappointing as they had given 

 good results in the laboratory. 



To test the effect of keeping lime mixtures for some time before 

 applying them the following formulae were tried with the results 

 included in the table below: 



Result after two months 

 Stuck better than (2) 

 Not so good as (1) 

 Came off very quickly 



Somewhat better but not good 



From results from (1) and (2) it is clear that it is best when possible 

 to keep the lime mixture at least some hours before applying. This 



