30 



INJURY BY SMELTER WASTES. 



0.09 per cent. It is evident that the amount found in the dump 

 can not account for the 66 tons of arsenic that go to waste; hence 

 a consideral:>le quantity must be vohitilized. According to the inves- 

 tigations of Harkins and Swain, previously mentioned, the average 

 amount of arsenic trioxid thrown off in the smoke (hiring twenty- 

 four hours is 59,270 pounds. Here flgain, however, as in the case of 

 the sulphur compounds, the quantity of ore used was not given. 



It is next necessary to show whether or not the escaping arsenic 

 settles on the surrounding forage crops in large enough amounts 

 to be injurious to cattle. For this purpose 20 samples of range grass 

 and such cidtivated crops as alfalfa were collected at distances vary- 

 ing from 1 to 10 miles from the smelter in various directions, but 

 more especially down the Deer Lodge Valley. These samples were 

 examined for total and soluble arsenic. The results obtained, calcu- 

 lated to a dry basis and expressed both as milligrams of arsenious 

 oxid per gram of sample and grains of arsenious oxid per daily ration 

 of 25 pounds, are given in Table YI. 



Table VI. — At'scnic content of forage expressed as arsenious oxid. 

 [Calculated to dry basis. J 



" Supposed to have killed cattle. 



From this table it is seen that arsenic was found in considerable 

 quantities in every sample examined. In order that the cattle in this 

 region may live at all it is evident that they must become confirmed 

 arsenic eaters. Through the courtesy of Dr. D. E. Salmon the writer 

 was able to examine microscopic sections and gross specimens of 

 the viscera of a number of cattle that it was thought had been killed 



