94 FORESTRY IN SPAIN. 



From the use made in English of the word tax, and its 

 derivatives, which in popular discourse, if not also in 

 scientific discussions, are applied to what is exacted by the 

 State directly or indirectly from members of the community, 

 some difficulty may be experienced in receiving it as it is 

 used in connection with forest economy on the Continent, in 

 which the term taxation is applied to the determination of 

 what produce a forest may yield, without injury to itself 

 and with advantage to all concerned. Taxation, or the 

 determination of this is a necessary operation in the profit- 

 able and scientific exploitation of a forest. It follows the 

 survey and preparation of an inventory, and the presentation 

 of a report on the conditions as to the growth and the vigour 

 of vegetation of a forest. It has for its object to ascertain the 

 quantity of wood material contained in a separate portion, or 

 in an entire wood, and to determine the laws of its increase. 



By Professor D. Francisco de P. Arrillega, member of 

 the Corps of Forest Engineers, and Professor in the School 

 of Forestry, it was seen that to facilitate important studies 

 there was required a text book of formulas and tables 

 required in the valuation of forests. Such a work was 

 published by Dr. Gustav Heyer, Director oi the School of 

 Forestry in Munden, a man deservedly held in high 

 estimation throughout Germany, and amongst students of 

 forest science in other lands. This Senor Arrillaga 

 translated into Spanish, and in 1872 it was printed by 

 the Government at the National Press, under the title 

 Compendia de Valoracion de Monies. According to the defini- 

 tion of Dr. Heyer the valuation uf forests is that department 

 of Dasocracia or forest economy, which has for its object 

 the determination of : 1. The value of the ground by 

 itself. 2. The value of the entire vegetable covering of this. 



3. The value of the forest trees, and arborescent productions. 



4. The annual rent or revenue of the ground, of the 

 vegetable covering, and of the forest. The designation 

 forest being now applied to the ground, and the vegetable 

 covering and the trees growing upj;i it conjointly. And iq 



