14 



EMORY OAK IN SOUTHERN ARIZONA. 



TANNIN POSSIBILITIES. 



The use of the tannin content of Emory oak has often been sug- 

 gested, although the tannin would be very dark colored unless 

 clarified. In the scarcity of other tannic agents it ought to furnish 

 the supply for an industry in its region. Table 5 shows the quantity 

 and sources of the tannin in the three most prominent oaks of 

 Arizona. 



TABLE 5. Tannin content of the different parts of Emory oak, Arizona white oak, 



and blue oak. 



According to Table 5, Emory oak shows a fairly rich tannin con- 

 tent 7.4 per cent in the bark at the base of the tree, as compared 

 to the average for American tanbarks of about 10 per cent. The 

 prospects for the commercial use of Emory oak are limited to the 

 Southwest, but they seem so good there that its possibilities should 

 be thoroughly studied. 



OTHER USES. 



There is but little activity in mining in the region, but even in the 

 past, when the mines were being worked, Emory oak was rarely used 

 for mine timbers. Yet most of the available conifers have been cut, 

 and, as the region is very rich in minerals, there is likely to be a strong 

 local demand for mine timbers, for which Emory oak will be used to 

 some extent with other native oaks. 



Though it is not of high value for posts, there is a limited use, 

 in the absence of good post material. 



