22 



INJURE TO VEGETATION BY SMELTER FUMES. 



TABLE 8. Study of sulphur trioxid content of foliage of trees, etc. Continued. 



TREES WEST OF SMELTER. 



In connection with this study it might be of value to give some 

 idea of the amount of sulphur dioxid that is given off each day into 

 the atmosphere by the smelter. Analyses of three samples of the ore 

 show that it contains 41.87, 40.08, and 42.44 per cent sulphur, or 41.46 

 per cent sulphur on the average. Since in extracting the copper the 

 sulphur is nearly all -given off as sulphur dioxid, it seems safe to 

 assume that 90 per cent of the sulphur from this ore would be liber- 

 ated. Therefore a simple calculation will show that for each ton of 

 ore about 838 pounds of sulphur or 1,676 pounds of sulphur dioxid 

 would be given off into the atmosphere. The author has been informed 

 that this plant extracts 1,000 tons of ore per day. If such is the-case 

 it will be seen that the enormous quantity of 1,676,000 pounds of sul- 

 phur dioxid (or 748 tons) are given off each day. 



An analysis of the water from a creek which runs alongside the 

 smelter and empties into the Sacramento River was made, and it was 

 found that the water was not only very acid, but contained a trace of 

 arsenic and 1 milligram of dissolved copper per liter. It can easily 

 be seen that these constituents might have an extremely injurious 

 action upon fish, upon crops irrigated by the Sacramento, and upon 

 persons who might drink the water. 



GENERAL CONCLUSIONS. 



The following conclusions may be drawn from this investigation: 



1. Sulphur dioxid when present in very small quantities in the air 

 kills vegetation. 



2. Such injur}^ shows itself by the increased sulphur trioxid content 

 of the foliage. 



