398 PROTECTION AGAINST PLANTS. 



instruments may be used, as shown in the figures ; but this 

 would only be done for specially valuable trees or in orchards. 

 A mixture twenty parts by weight of wood-ashes with one 

 part carbolic acid may also be used. This is boiled and 

 smeared on the stems with a brush, and in a few days' time 

 all the lichens will fall off. Limewater has the same effect. 

 A .mixture of 3 Ibs. of blue stone, 2 Ibs. of lime, and 30 gallons 

 of water may also be used. It is best to remove lichens on 

 dry days in spring, or autumn, as, thus, numerous injurious 

 insects are also killed. 



iv. In Indian forests, woody climbers are cut periodically, 



Steel- wire brush. 



Ditto, with hole for handle. 



Fig. 195. Fig. 196. 



Tree-scraper. 



and especially two years before fellings, as they then rot and 

 no longer bind trees to be felled to others intended to remain 

 standing. 



SECTION II. SPECIAL ACCOUNT. 



The following is a list of the weeds most hurtful in the forests 

 of Central Europe, with an account of the special means of 

 combating them. It is best to consider them in order of their 

 demands on light and the amount of injury they do, and not 

 according to their systematic botanical arrangement. 



The following groups occur : 



1. Liyhtdemanders, which generally spring up on blanks 

 and felling-areas. 



2. Half-shadebcarers, occurring in the interior of woods as 

 soon as they become too light. All shrubs and herbs belong- 

 ing to this class grow all the better in the open. 



