552 Scientific Proceedings, Royal Dublin Society. 



After absorption with potassium hydrate : — 



Height of mercury in pressure tube, 

 ,, ,, in burette, 



Pressure of gas after absorption of C0 2 , 

 Tension of C0 2 , 



After absorption with pyrogallic acid : — 



Height of mercury in pressure tube, . . 509-5 511-0 

 „ „ in burette, . . . 351-0 351-0 



Pressure of nitrogen, . . . . . 158-5 160-0 

 Capacity of burette at 14 c.c. division line = 14-2267 c.c. 



The parts per 100,000 of organic carbon and total nitrogen 

 contained in sewage are calculated from the above determinations 

 in the ordinary way. 



Analysis No. I. gives : — 



4*9 parts carbon per 100,000 

 6-96 parts nitrogen per 100,000 



Analysis No. II. gives : — 



5-1 parts carbon per 100,000 

 7-02 parts nitrogen per 100,000 



(II.) Analyses of air. About 175 c.c. air at ordinary pressure 

 taken. 



All measurements made at the 100 c.c. line on burette. Open 

 pressure tube employed. 



Heigbt of mercury in pressure tube, 

 Atmospheric pressure, 



Total pressure, .... 

 Height of mercury in burette, 

 Pressure of the gas, . 





