69 
will give an analysis made by the ammonia process,” the 
“ permanganate process,” and the “ chromic acid process,” 
the sample being one taken from the Irwell at Throstlenest, 
on the 19th of February, 1886, and the results are expressed 
in grains per gallon : — 
(1) Free ammonia 0’196. 
Albuminoid ammonia ... 0’226. 
(2) Oxygen required to oxidise the organic matter 
in 3 minutes, 1 hour, S hours. 
0*413. 1*442. 1*694. 
(3) Carhonic acid given off on heating to 96^ C. = 1*512. 
5 ) 
5 ) 
100" C. = 7*224. 
Carbonic acid estimated separately by pre- 
cipitation with ammoniacal barium chlo- 
ride solution (therefore as carbonates) ... = 2*681. 
Carbonic acid obtained by oxidation by 
means of chromic acid = 2*733. 
As the water was carefully heated to a temperature not 
exceeding 96° C., until all the dissolved free carbonic acid 
was liberated and no more was given off, it is clear from 
these results that the carbon of the 7'224 grains of carbonic 
acid gas given off on boiling the water (1*9701 grains) was 
derived from organic matter undergoing rapid decomposition 
at 100° C., and from no other source. 
I venture to think that a result of this kind shows the 
necessity of devising a method for the accurate determina- 
tion of the carbon in the water itself, and not by burning 
the residue obtained on its evaporation, and then measuring 
the amount of carbonic acid gas thus obtained. 
On comparing the total carbon obtained by my process 
(calculated from the two amounts of carbonic acid gas, viz..* 
7*224 + 2*733 = 9 057 002 = 2*667 carbon), with the amount 
of carbon corresponding to the amount of oxygen required 
to oxidise it in 3 hours, viz. : 2*329 grains of carbon, it is 
evident that there is a loss of 14*51 per cent of the carbon 
in the permanganate process, or in other words that process 
