24 BULLETIN 9, U. S. DEPARTMENT OF AGRICULTURE. 
expect to rent land m America at the Australian price of 4 cents an 
acre a year, there is nevertheless cheap and suitable land in Cali- 
fornia and the Southwest. 
TANNIN CONTENT OF CALIFORNIA BARKS. 
The first acacia barks analyzed by the University of California 
were those of Acacia decurrens mollis, A. decurrens dealbata, and A. 
pycnantha. In the report upon these barks‘ it was shown that the 
California-grown bark of mollis was twice as thick as that of dealbata 
of the same age and that it yielded about twice as high a percentage 
of tannin. This agrees very nearly with comparisons made upon 
barks grown in Australia and in Algeria. The actual tannin contents 
of these three barks grown at Berkeley were as follows: 
Per cent. 
Acacia Gecurrens mollis: c.2=2 esas eee eee eee 48.6 
Acaciaidecurren’s'dealbatals 22 3. anaes Cee eee eee 24.8 
Acacia pycnantha..- 4... ss.25 suet Son oo eee 46.8 
Dr. Hilgard states that these tannin determinations were made 
by the permanganate method, repeatedly checked by the gelatin or 
hide-strapped method, with but triflmg differences in the results, so 
that the figures fairly represent what hides will take up. 
One of the trees, 13 years old when cut for these experiments, was 
12 inches in diameter at 3 feet above the ground, and 40 feet high. 
It will be observed of these analyses that California-grown A. pyc- 
nantha bark, contrary to Australian experience, did not exceed mollis 
in richness of tannin content. Later analyses seem to confirm this 
generalfact: ThatA. decurrens normalis and mollis are proportionately 
richer in tannin when grown in California than when grown in 
Australia. As yet, however, the quantity of bark which has been 
produced is not sufficient to settle this teresting and important 
pomt, though everything poimts to the desirability of both of these 
forms of Acacia decurrens for planting in California, particularly in 
the Coast Range, where the bark so far tested has been grown. 
Another report ? gives some interesting statistics about the planta- 
tion at Santa Monica, which has been under charge of the University 
of California since 1894. This report states that Acacia decurrens 
and A. pycnantha, 25 months from seed (20 months planted in the 
field), have grown twice as rapidly as the same species mentioned in 
Australian reports. Many trees of this age had attained a height of 
16 feet and the very poorest were 2 inches in diameter and 9 feet 
high. Mr. Lyon estimated that at 4 years of age such a plantation 
would yield a crop of bark equal to that of 7 or 8 year old Australian 
groves; that is, from 80 to 90 pounds of bark to a tree. 
1 Report of Dr. Hilgard, Jan. 23, 1884. 
* Third Annual Report of the First Board of Forestry of California; Chapter on Acacias, by W. G. 
Lyon, State Forester, 1890. 
