SULPHUR TRIOXID IN FOLIAGE ABOUT ANACONDA. 



25 



SULPHUR TRIOXID IN THE FOLIAGE OF TREES AROUND WASHOE 



SMELTER. 



The samples of injured foliage near the smelter and of uninjured 

 foliage of the same species of trees beyond the apparent range of 

 smoke damage, collected on the trips enumerated, were examined for 

 sulphur trioxid and ash and the results were compared, as in the Ten- 

 nessee investigation. The soils beneath the injured and uninjured 

 trees were examined for sulphur trioxid, to determine whether any 

 increase in the sulphur trioxid of the injured leaves could be due to 

 an increased amount of this constituent in the soil. In the followino- 

 table are ofiven the results obtained : 



Table III. — Sulphur trioxid in foliage, in ash, and in soils around Washoe smelter. 



[Calculated to dry basis.] 

 NORTH OF SMELTER. 



3881 (J— Bull. 118—10- 



