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methods foe the deteemin-atio^^ of 

 Method 11. 



Absorbent materials : (a) purified glass-wool, (b) acidulated perman- 

 ganate solution. 



Absorption apparatus : two small Erlenmejer flasks, connected by 

 rubber tubing; modification of Uffelmann's apparatus. 



TABLE III. 



No. of 



Date, 



experi- 



1895. 



ment. 





1 



7-VI 



2 



7-VI 



3 



8-VI 



4 



10- VI 



5 



20- VI 



6 



21-VI 



7 



22- VI 



8 



24- VI 



9 



24- VI 



10 



26- VI 



11 



26-VI 



12 



26-VI 



13 



2- VII 



14 



2- VII 



15 



2- VII 



16 



3- VII 



17 



3-VII 



18 



3-VII 



19 



8-VII 



20 



8-VII 



21 



8-VII 





Time 







Amount of 



taken 



Source of 





air aspirated. 



in aspi- 

 rating. 



the air. 





30.0 L. 



1 hour 



Room 



Closed 



25.0 " 



1 " 





(( 



30.0 " 



1 " 





'•' 



27.0 " 



1 " 





a 



7.3 " 



2ihrs. 





a 



8.8 " 



5 " 





a 



6.7 " 



3^ " 





li 



7.5 " 



5^ " 





Open 



8.3 '' 



5f " 





" 



5.5 '' 



44- " 





u 



8.0 " 



3| " 





(( 



10.0 " 



3f " 





(( 



8.4 '' 



U " 





Closed 



8.25" 



5i " 





a 



12.1 " 



5i " 





(I 



17.3 " 



5i" 





Open 



8.0 " 



H " 





a 



8.4 " 



5i " 





" 



7.6 " 



64 " 





<( 



8.05" 



64 " 





(( 



10.2 " 



6 " 





i( 



Mgs. of O consumed for 1 

 cbm. of air. 



Gaseous form. Dust-form, 



0.31746 



13.33333 



0.63492 



0.35273 



19.56947 



54.11255 



0.00000 



19.04761 



5.73723 



17.65224 



8.82612 



19.41747 



5.75109 



5.75109 



5.75109 



19.64195 



33.90776 



43.05748 



25.42588 



6.00114 



4.73619 



mgs 



80952 mg& 



09523 



63492 



17637 



56947 



23376 



32196 



39420 



42340 



81553 

 50218 



50654 

 67989 

 11812 

 45307 

 49529 

 00912 

 94476 



This table shows analyses made on room- air, mostly in duplicate and 

 triplicate, with separate estimations of the gaseous and of the dust-form 

 of organic matter. The results obtained in simultaneous determinations 

 on the same air show a marked variation. This variation in the results 

 seems to be intimately connected with the quantity of air that was 

 aspirated through each apparatu.s ; the greater the quantity of air aspi- 

 rated the smaller the relative proportion of organic matter found, both 

 as to the gaseous and the dust-form of organic matter. There is no in- 

 dication from the results obtained of any definite relation between the 

 quantity of organic matter in gaseous form to that in the form of 

 dust. 



The objections to this method are that the amounts of the absorbent 

 materials are quite small and consequently incapable of absorbing any 

 material portion of the organic matter from the air passed through them. 

 The small quantity of absorbent material also necessitates the aspiration 

 of the air in very slow current. The results obtained are quite variant 



