ON THE DETERMINATION OF ORGANIC MATTER IN WATER. 337 
Campbell at the late meeting of the British Association gave an account of ex¬ 
periments made by himself, which, to a certain extent, negative the conclusion 
arrived at by these gentlemen. His experiments, which appear to have been 
conducted with care, seem to show that urea is certainly decomposed entirely 
when distilled with carbonate of soda, but only when in extremely dilute 
solutions ; it requiring the assistance of permanganate of potash to decompose it 
even when so dilute as in the proportion of the ^ part of a grain in a gallon 
of water, or one part in five millions, and requiring the assistance of caustic 
potash to decompose it, even when diluted to an extent above one part in seven 
millions, and that it is only decomposed by carbonate of soda alone when diluted 
somewhat above this point. In dealing with albumen, also, he asserts that a 
distinct quantity of ammonia is evolved by carbonate of soda ; and likewise that 
in all cases, after the ammonia has been evolved as far as possible by carbonate 
of soda, caustic potash evolves not even a trace of ammonia, and it is only 
on the addition of permanganate that the final quantity of nitrogen is expelled 
as ammonia. It is likewise affirmed that as in very dilute solutions of urea 
all the nitrogen is expelled as ammonia by the carbonate of soda, so like¬ 
wise this is practically the case in very dilute solutions of albumen. It must 
be confessed that some difficulties stand in the way of the general application 
of the process recommended by Messrs. Wanklyn, Chapman, and Smith. In 
the first place, it is not by any means possible in all cases to estimate the am¬ 
monia ready-formed in water without previous distillation ; and, again, we are 
hardly yet in a position to class the nitrogenous matters under the respective 
heads of urea and albuminoid matter, inasmuch as we have, as already ex¬ 
plained, no knowledge, more than such as is extremely general in character, 
of the matters introduced by infiltration of sewage. 
The opposing results obtained by chemists of such acknowledged ability are 
in themselves testimony of the difficulties of the subject. 
Dr. Frankland's Experiments .—The nitrogenous portion of the organic matter 
being the acknowledged cause of the deleterious character of such water as con¬ 
tains it, all experiments upon the subject will tend naturally to the determina¬ 
tion of the nitrogen existing in this particular form. Dr. Frankland goes, 
however, one step further; in addition to the nitrogen he examines the amount 
of carbon in a water residue, exclusive of that contained in the mineral car¬ 
bonates. Accordingly, his process, although it assumes a rather more compli¬ 
cated character, is certainly one which aims at considerable precision. The fol¬ 
lowing operations are necessary :— 
1. Determination of the carbon contained in the organic matter, called, by 
way of distinction, “ organic carbon.” 
2. Determination of the total combined nitrogen. This nitrogen may exist 
in the w r ater in one or more of the three following forms :— a. As a constituent 
of organic matter, “ organic nitrogen.” b. As a constituent of mineral nitrites 
and nitrates, c. As a constituent of ammonia. 
3. Determination of the nitrogen present as nitrites or nitrate’s. 
4. Determination of ammonia. 
By deducting the sum of the nitrogen existing as nitrates and nitrites, and 
that present in the ammonia from the total combined nitrogen, the remainder 
will be the amount of organic nitrogen. 
The experiments are at present in a state of incompleteness, and have not yet 
been published in extenso. The method adopted by Dr. Frankland of express¬ 
ing his analytical results are worthy of careful study. The following is an 
abstract of the report upon the metropolitan waters for June, in the present 
year, it will convey a clearer idea than description would do of the plan pur¬ 
sued :— 
VOL. IX. 
Z 
