﻿AN ECONOMIC STUDY OF ACACIAS. 



25 



There are reports of trees of Acacia decurrens mollis in southern 

 California which when 4 years old were 30 feet high and 8 inches 

 in diameter. 



A complete analysis of the tanbarks grown at Santa Monica 

 Forest Station, made in June, 1898, by Mr. George Colby, of the 

 California Experiment Station, gives the following results: 



Water-free 

 substance. 



Acacia decurrens normalis: 



Bark, main tree 



Bark, branches 



Bark, large roots 



Acacia decurrens mollis: 



Bark, main tree 



Bark, branches 



Bark, large roots 



Acacia pycnantha: 



. Bark, main tree 



Bark, branches 



Bark, large roots 



Water in 



Tannin in 



air-dried 



air-dried 



bark. 



bark. 



Per cent. 



Per cent. 



6.53 



42.48. 



8.28 



36. 57 



5.28 



31.35 



7.60 



• 45.98 



8.08 



42.98 



7.89 



32.37 



9.32 



41.80 



8.67 



38.66 



7.10 



47.02 



Per cent. 

 45.83 

 39.98 

 33.10 



49.76 

 46.66 

 35.18 



46.09 

 42.34 

 50.58 



Two points are brought out by these analyses: Acacia pycnantlia 

 alone showed a higher proportion of tannin than a bark with a large 

 root, although this fact is likely to be true of the various forms of 

 Acacia decurrens. The superior value of Acacia decurrens mollis is 

 plain. All of these barks gave good results in practical tests by 

 tanners. It should be stated that these results were not obtained 

 from commercial plantations, and that notwithstanding the figures 

 which were presented so many years ago by the University of Cali- 

 fornia, no commercial plantations were set out. The principal reason 

 for this was that at that time the demand for tanbark in California 

 was sufficiently supplied by tanbark oak, which was then abundant; 

 moreover, public attention had not been then directed to the possi- 

 bilities of forest planting for timber, tanbark, and other products. 



ACACIAS FOR TIMBER. 



Throughout the world there is evidently an increasing demand for 

 hardwoods. In the eastern United States, which probably furnished 

 the best supply of hardwood lumber that has ever been known, the 

 diminution of the supply has already caused readjustments in several 

 industries which have depended upon it. 1 The foresters of South 

 Africa, Algeria, and Australia are planting tons of acorns to grow 

 future hardwood forests. California in particular, rich in conifers, 

 has no hardwoods of commercial importance, and the introduced 

 eucalypts present many difficulties in utilization. 



Principal Timber Species. 



Many of the acacias furnish useful and valuable timber and are not 

 only beautiful in grain but durable in contact with the ground. Even 



1 Circular 116, Forest Service, U. S. Department of Agriculture, the Waning Hardwood Supply. 



