10 
BULLETIN 70 6, U. S. DEPARTMENT OF AGRICULTURE. 
extract, which contains usually from 22 to 24 per cent of tannin and 
is sold on the basis of its strength, has ranged for the past few years 
as follows : In 1929, from 5% to 9% cents ; in 1930, from 6% to 9% 
cents; in 1931, from 5 to 9% cents; in 1932, from 4% to 5% cents; in 
1933, from 4:% to $% cents; and in 1934, from 4% to 6% cents. 
A pound of extract contains approximately the same amount of 
tannin as a pound of properly gathered and cured leaf. In making 
the extract the tannin is extracted with large quantities of water 
which must be evaporated in expensive copper pans under skilled 
supervision and at some expense for fuel. When the extract is to be 
used, as much or more water than was evaporated in making it is 
added to secure a tanning or dyeing solution of the desired strength. 
The consumer, however, often prefers to use the extract, rather than 
to make his cwn liquor from the leaf. 
DISPOSAL OF EXTRACTED MATERIAL. 
So far as can be learned, no really satisfactory method of disposing 
of the extracted leaves is in general use. The material is placed in 
large piles or ricks, or taken to fill in waste places. A small quantity 
is used on farm land as a top-dressing to be plowed under. Analyses 
of the commercially extracted material given in Table 5 show its 
fertilizing value. 
Table 5. — Fertilizing value of commercially extracted sumac leaves and leaf 
stems and stalks. 
Part of plant. 
Mois- 
ture. 
Cal- 
cium 
oxid. 
Potas- 
sium 
oxid. 
Phos- 
phorus 
pen- 
toxid. 
Ash. 
Sample 
No. 
Total. 
Cal- 
cium 
oxid. 
Potas- 
sium 
oxid. 
Phos- 
phorus 
pen- 
toxid. 
32479 
Leaves and leaf 
Per cent. 
5.70 
5.33 
4.59 
4.59 
Per cent. 
1.66 
1.95 
1.31 
1.44 
Per cent. 
0.11 
.09 
.39 
.17 
Per cent. 
0.23 
.20 
.15 
.11 
Per cent. 
5.13 
5.32 
3.43 
3.24 
Per cent. 
32.36 
36.65 
38.19 
41.36 
Per cent. 
2.14 
1.69 
11.37 
5.24 
Per cent. 
4.48 
32482 
32479 
do 
Stalks 
3.76 
4.37 
32482 
do 
3.39 
Examination of a number of unextracted sumac samples gave: 
Ash, 4 to 7.5 per cent ; potassium oxid, 1.18 to 2.15 per cent. The 
ash of these samples contained from 25 to 30 per cent of potassium 
oxid. 
Comparison of the percentage of potassium oxid (K 2 0) in the 
original material and in the water extract, as obtained for the tannin 
analysis, shows that although the unextracted sumac contains rather 
high percentages of potassium oxid, this is almost entirely removed 
on extraction. These experiments were made on finely ground su- 
