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METHODS FOE THE DETERMINATION OF 



remaining in solution then estimated by titration with ■— ammonium 

 hydroxid. The results obtained show the absence of ammonia in the 

 room-air, while the quantity of ammonia in the air of the soil pipe 

 appears to be of fairly constant proportions. This method appears to 

 be sufficiently reliable for general use. The importance of the results 

 obtained rests mainly upon the fact that they indicate to what extent 

 the ammonia in the air, under certain conditions, may become a factor 

 in the determination of organic matter in air with any of the methods 

 in use. 



TABLE X. 



No. of ex- 



Date, 1895. 



Am cunt of 

 air 



Time 

 taken in 



Source of the 



With or 

 without 



Mgs. of NH3 in 1 cbm. 



periment. 





aspirated. 



aspirating. 



air. 



dust-fllter. 



of air. 



1 



8-VII 



110.5 L. 



7 hrs. 



Room 



Without 



0.0000 mgs. 



2 



8-VII 



118.3 '' 



7 " 



Sewer pipe 



(( 



0.8450 ' 





3 



23-X 



8.25 " 



5 '• 



Room 



a 



0.3030 ' 





4 



24-X 



8.0 " 



2f " 







li 



0.2500 ' 





5 



25-X 



8.0 " 



4i " 







With 



0.0000 ' 





6 



25-X 



8.0 " 



4i ;; 







Without 



0.1875 ' 





1 



7-XI 



119.4 " 









With 



0.0000 ' 





8 



7-XI 



73.0 " 



22i " 







Without 



0.0000 ' 





9 



8-XI 



68.2 " 



24^ " 







With 



0.0000 ' 





10 



8-XI 



57.5 " 



24 " 







Without 



0.0000 ' 





11 



9-XI 



204.9 " 



24 *' 







With 



0.0360 ' 





13 



9-XI 



138.75 " 



24 " 







Without 



0.0029 ' 





13 



10-Xl 



131.5 " 



23f " 







With 



0.0000 ' 





14 



10-XI 



88.25 " 



23| " 







Without 



0.0056 ' 





15 



ll-XI 



186.2 " 



23| " 







With 



0.0000 ' 





16 



11-XI 



212.0 " 



23i " 







Without 



0.00235 ' 





17 



12-XI 



82.0 " 



23i " 







With 



0.0000 ' 





18 



12-XI 



192.5 " 



23^ " 







Without 



0.0000 ' 





19 



13-XI 



157.6 " 



251 " 







With 



0.0000 ' 





20 



13-XI 



109.0 " 



25i " 







Without 



0.0000 '* 



This table shows analyses made by aspirating the air through 100 

 c. c. of twice distilled water, and testing with Nessler's reagent ; thus 

 estimating directly the amount of ammonia in the air. Usually two 

 simultaneous' tests were made on the same air, the one with, and the 

 other without, the attachment of a dust-filter. There appears to be 

 some evidence of the direct influence of the dust of the air on the 

 results obtained in this manner, though at times no ammonia was 

 found even without the use of the dust-filter. At all times the 

 quantities of ammonia found were quite small. 



Method YI 



Absorbent material : a yu- solution of iodine. 

 Absorption apparatus : a Pettenkofer absorption tube. 



