KESULTS OF INVESTIGATION, TENNESSEE. 



17 



is believed that the injured trees to the south can be compared with 

 the uninjured trees beyond tlie range of significant damage in an 

 easterly direction Avith perfect satisfaction, and that the results of 

 such a comparison will be just as accurate as though such uninjured 

 samples had been taken beyond the smoke range to the south. 



It should be borne in mind that two smelters were involved in the 

 above investigation, which were situated so close to one another that it 

 was impossible to say which })robably was causing the damage. 

 Hence a point midAvay between the two was chosen as the most con- 

 venient point from which to reckon all of the distances given in 

 Table II. 



Table II. — ^Sulphur trioxld in foliage, in ash, and in soils around smelters. 



[Calculated to dry basis.] 

 NORTH OP SMELTERS. 



38816— Bull. 113—10- 



