250 Scientific Proceedings, Royal Dublin Society. 
completely air-dry, and then submitted a portion to analysis, with 
the following results :— 
Insoluble mineral matter, . : : : 12°16 
Moisture, . . 15°68 
Organic matter reslable 3 in dilate HCl, . 4:00 
Organic matter soluble in dilute HCl, . . 4°85 
MnO, . : : : : : . 24:60 
Cad; & : : 3 : : : ae) VAST) 
Fe,0, / 
41,0) oe 
MeO: ! : : : : é 2 4560 
pAal 110 
K,0, 
GND OR ee: ; : Y : : .  0:005 
NiO, 
CoO, | traces 
Zn0, 
COMTI ie wa Mame OE fs 1 QoN5 
SOs; : : ‘ : : ! 2 (Ora, 
Oa: : ' i : : ; . 0°59 
Cl, ; i : : : ‘ : . trace 
100°695 
It is evident from the above results that the manganese was 
present mainly as manganous carbonate. <A careful examination 
was made for peroxide, but with negative results. An examina- 
tion for nitrates was also attended with negative results. 
No trace of sulphuretted hydrogen, or other products of 
putrefactive fermentation, such as are invariably met with when 
sewage solid matters alone are kept under similar conditions, were 
detected. 
The organic matters associated with manganous carbonate 
were found to be of considerable interest. A combustion of 
some of the air-dried substance gave the amount of organic carbon, 
after allowing for the inorganic carbon, as = 4°7 per cent., and a 
determination of the organic nitrogen by Kjeldahl’s method gave 
0-67 per cent. 
As will be gathered from the Table giving the results of 
analysis, a portion of the organic matters present was taken up by 
