SOURCES. 
63 
United States, one from Texas on the Q. virens, or live- 
oak, is said to closely resemble Aleppo galls, and to 
contain 40 per cent, of tannic acid. Another variety, 
from California, formed on Q. lobata, is soft and 
spongy but very astringent. 
Dr. Squibb in 1873 stated that American galls from 
oak and sumac have been found valuable sources for 
gallic acid. 
In 1890 galls collected in the vicinity of Philadel¬ 
phia by the author from the leaves of Q. alba in the 
month of July, and identified by Mr. L. O. Howard, 
entomologist of the United States Department of Agri¬ 
culture, as having been produced by the insect Acraspis 
erinacei, were found to contain 17.89 per cent, of tan¬ 
nic acid. The moisture was found to be 45.95 per cent., 
and ash 0.60 per cent. These galls are found most 
abundantly on the young white oaks, and may be recog¬ 
nized by their covering of purple spines. Another 
variety collected in August from the twigs of the same 
oak, and identified by Mr. Howard as “a Dipterous gall 
made by some species of Cecidomyia or Diplosis” was 
found to contain as an average of three estimations 
9.34 per cent, tannic acid, 73.19 per cent, of moisture, 
and 0.46 per cent, of asli. The same variety rapidly 
dried by artificial heat at about 80°, so as to destroy 
the insect, yielded 31.68 per cent, of tannin, 11.34 per 
cent, of moisture, and 2.6 per cent, of ash. Another 
variety, also collected in August, from the leaves of Q. 
palustris , and stated by Mr. Howard to have been pro¬ 
duced by Holcarpis globulus, Fitch, gave 3.91 per cent, 
tannic acid, 58.73 per cent, moisture, and 0.77 per cent, 
ash. 
