METHODS OF ANALYSIS. 57 



From these data it will be seen that arsenic was found in consid- 

 erable quantities in every sample of range grass examined, and in 

 most cases a large portion of the arsenic was in a water-soluble condi-' 

 tion. It seems hardly necessary to add that such grass as this is not 

 fit for a feed for animals, 



CONCLUSIONS. 



From the investigations made in the vicinity of Anaconda during 

 the summer of 1908 the following conclusions relative to conditions 

 at that time may be drawn : 



(1) The forests around the smelter appeared from actual chemical 

 analysis to be injured for at least 10 miles north of the smelter, 11| 

 miles east of the smelter, 9^ miles south of the smelter, and 15 miles 

 west of the smelter. 



(2) This injury to forests by sulphur dioxid undoubtedly extended 

 to a distance of 15 to 19 miles north of the smelter, 11| to 14 miles 

 east of the smelter, where damage from the Washoe smelter and the 

 Butte smelters probably overlapped, 10 miles south of the smelter, 

 and 18 to 19 miles west of the smelter. The damage may have 

 extended even farther in certain localities, although this was not 

 proved by chemical analysis. 



(3) The injury to forests in a southerly and westerly direction 

 extended farther from the smelter in the summer of 1908 than in the 

 summer of 1906. 



(4) As in the previous investigations, it was noted that the junipers 

 were very resistant to smelter fumes, while the red firs were very 

 susceptible and were badly damaged at distances of from 18 to 19 

 miles from the smelter; the lodgepole pines were damaged for at 

 least 10 or 11 miles. 



(5) Large quantities of arsenic were discharged from the smelter 

 and settled on the grass of government ranges at distances as great 

 as 15 miles from the smelter. Such arsenical range grasses are not a 

 suitable feed for cattle. 



METHODS OF ANALYSIS USED IN INVESTIGATIONS. 



FOLIAGE OF TREES. 



Moisture. <^ 

 Dry a convenient quantity (about 2 grams) of the substance in the boiling-water 

 bath until the material ceases to lose weight. 



Ash.a 



Char a convenient quantity of the substance, representing about 2 grams, at the 

 lowest possible heat. Exhaust the charred mass with water, collect the insoluble 

 residue on a filter, burn till the ash is white or nearly so, and then add the filtrate to 

 the ash and evaporate to dryness. Heat the whole to low redness and weigh. 



« Official and Provisional Methods of Analysis, U. S. Dept. Agr., Bureau of 

 Chemistry Bui. 107, Rev. 



