110 
PROFESSOR P. F. FRANKLAND AND MRS. G. C. FRANKLAND ON 
I. 
n. : 
grm. 
grm. ^ 
Potassium pbospliate. 
•0.5 
•05 1 
Magnesium sulphate. 
•01 
•01 
Calcium chloride. 
•05 
•05 
Ammonium carbonate. 
1-00 
1-00 
Grape sugar.. . . 
1-00 
none 
V--- —.7 
V ! 
in 1000 c.c. of 
in 1000 c.c. of 
distilled water. 
distilled water. 
After remaining three days at 30° C. the solutions exhibited traces of nitrous acid as 
indicated by the iodide of starch reaction. After six days this reaction was decidedly 
stronger, but still the c[uantity of nitrous acid was not sufficient to admit of quanti¬ 
tative estimation. The experiments were repeated again with slight modifications, 
but again the amount of nitrous acid was insufficient for quantitative purposes. Upon 
this evidence, unsupported as it is by a single instance of nitrification on such a scale 
as to admit of the quantitative determination of the nitrous and nitric acids formed, 
Her.eus claims for the organisms p, cr, (f), and y the nitrifying power. This is the 
more remarkable, as nitrous and nitric acids are so eminently fitted for quantitative 
estimation, even when present in only the minutest traces. He even goes fui'ther and 
claims similar oxidizing properties for the well-known forms Micivcoccvs j^i'odigiosus, 
B. ramosus, the cheese Spirilla, Tinkler’s Spjirilla, the typhoid hacillus of Koch- 
Gaefky, B. anthracis, and Staphylococcus citreus, having obtained nitrous acid 
reactions when these organisms were respectively grown in sterilised and diluted 
urine. So positively, indeed, is it asserted in the above paper, that the organisms in 
question are endowed with nitrifying jiroperties, that a casual reader will almost 
infallibly carry away the impression that the conclusions drawn are altogether beyond 
dispute. It is in this way, no doubt, that Herjeus’s statements have been generally 
incorporated without question in the ordinary text-book literature of the day. 
Hera:us’s investigations were obviously calculated to be of the greatest importance 
to all interested in the question of nitrification, but his conclusions concerning the 
nitrifying power of the bacteria designated by p, cr, (f), and y did not admit of imme¬ 
diate criticism, and could not be controverted or verified without a lengthy experi¬ 
mental inquiry. On the other hand, his assertions concerniiig the nitrifying properties 
of the well-known organisms mentioned above could be easily put to the test b}^ any 
one possessing pure cultures of the same forms. Now, in the course of an investigation 
on “ The Action ol some Specific Micro-organisms on Nitric Acid ” (‘ Chem. Soc. 
Journ.,’ 1888, p. 373), one of us had occasion to experiment with two of the same 
organisms, viz., M. pu'odigiosus and B. ramosus, but in the case of neither could any 
evidence of nitrifying power be obtained, whilst, on tlie contrary, both organisms Avere 
found to be capable of reducing nitric to nitrous acid. This observation at once 
