376 



Mr. H A. Smith on some Points in the 



Table VI. 



Flue leading from Condensing-towers to Chimney. 



Amount of air taken for each analysis = 500 cubic feet. 



Amount of air passing = 



31,722 cubic feet per hour. 



No. of analysis. 



As^O^ per 1000 

 cubic feet. 



Amount per hour. 



Amount per day. 





grain. 



grains. 



grains. 



1. 

 2. 

 3. 



0068 



2157 



51-768 



0-082 



2601 



62-424 



4. 



0072 



2-284 



54-816 



5. 



0102 



3-235 



77-640 



6. 



0064 



2030 



48-720 



7. 



0198 



6-280 



l.iO-720 



8. 



0248 



7-867 



1 88 808 



9. 



01S6 



5900 



141-600 



10. 



0-232 



7-359 



176-616 



11. 



0-262 



8-311 



199-464 



12. 



0-382 



12117 

 60141 



290-808 



1896 



1443-384 



Mean 



0-158 



5012 



120-282 





Closely connected with this is the specimen of 

 Air taken 10 feet from bottom of chimney. — The same amount 

 of air was taken for each analysis in this case as in the former, 

 namely 500 cubic feet, the mean of nine analyses in this case 

 being 



As^O' 

 per 1000 cubic feet. 



0-086 grain, 



or nearly ^q gr. per 1000 cubic feet. Surely such a state of things 

 ought to be prohibited. The arsenious acid thrown into the atmo- 

 sphere must in some places be very large. Of its danger there can 

 be no doubt. But the great problem will be how to prevent its 

 escape. It is owing to no carelessness on the part of the manu- 

 facturers ; and it is one of those things that in our present state 

 of knowledge it is scarcely profitable to remove. On whom must 

 the blame rest ? 



