758 JOURNAL OF FORKSTRV 



sulphuric and hydrochloric acids are deposited annually per square 

 meter of soil. Lime also combines with poisonous zinc, copper, iron, 

 and mercury salts and renders them harmless to plants, but has little 

 or no effect on arsenic compounds. Some of these compounds in 

 small quantities stimulate plant growth, but in large quantities hinder 

 or destroy it. Dust from lime, cement, or magnesite ovens, etc., may 

 act as a fertilizer, or if in too great volume and not occasionally har- 

 rowed into the soil may form a crust which will injure vegetation. 

 Soot does not in itself injure plants, but does so indirectly by sticking 

 on the foliage and adsorbing other poisonous gases from the air. In 

 case of many substances, such as calcium, magnesium, chlorine, fluor- 

 ine and sulphur compounds, which are already present in soil not 

 exposed to smoke, it is difficult to determine the amount of injury 

 due to fumes, since chemical analysis of the plants will not show 

 the origin of the poisons they may contain. W. N. S. 



(Graf zu) Leningen-Westerburg. Rauchschiiden und cinschldgige boden- 

 kundliche Fragcn. Forstwiss. Centralbl. 42 : 18-93, 1920. 



Fabricius describes the silvicultural system 

 Nezv Form used by Dr. Eberhard in the Langenbrand forest 



of Shelter- ( Wiirttemberg). This consists of a preparatory 



wood Cutting stage, in which the stand is prepared for repro- 

 duction by repeated moderate thinnings and a 

 stage of removal cuttings beginning about 5 years after reproduction 

 is established. The preparatory cuttings are primarily to get rid of 

 raw humus, which may also be removed by hand either over the 

 whole area or in seedspots. These cuttings also make room for re- 

 production, especially of tolerant species, to start. The removal cut- 

 tings are rather light, and repeated every year if practicable. They 

 begin in the interior of the stand and progress outward, beginning 

 with small openings, which are gradually enlarged into a wedge shape 

 with the point toward the wind. The shape of opening is not definite, 

 but may be varied to suit local conditions. Damage from storms and 

 logging is reduced to a minimum, and natural reproduction is very suc- 

 cessful. Of the whole area, 92 per cent has been reproduced natu- 

 rally. The principal characteristic which distinguishes this from cer- 

 tain other methods is the shape and arrangement of the cuttings so as 

 to eliminate damage from logging and from winds. W. N. S. 



Fabricius, L. Waldban-Lehrgang im Gebiet des Langenbrander Schirmkeil- 

 schlages. Forstwiss. Centralbl. 42: 233-237. 1920. 



