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PROFESSOR P. P. FRANKLANU AND MRS. G. C. FRAI^KLAND OX 
the conditions affecting the process of nitrification, in a very elaborate paper commu- 
iiicated to the Chemical Society in the following year (1879, pp. 429-456). 
In subsequent publications (‘ Compt. Rend.,’vol. 89, pp. 891 and 1074), Schlcesing 
and Muntz claim to have separated the organism causing nitrification, and they 
briefly descidbe the general appearance which nitrifying media present when examined 
Avitli high microscopic powers. 
It is, however, almost needless to say that we have no guarantee that they actually 
accomplished the isolation of this important organism, as the methods of bacterio¬ 
logical research at that tiine in general use were of a very imperfect character. In any 
case, the subject demanded re-investigation with the aid of more modern methods. 
The results of a number of other researches on the subject of nitrification have been 
published from time to time, amongst which we may specially mention an extremely 
interesting paper by Muneo (‘Chera. Soc. Jonrn.,’ 1886, pp. 632-680), in which the 
nature of the nitrogenous substances capable of undergoing nitrification is very fully 
discussed. In none of these communications, however, is any material advance made 
towards the identification [ind isolation of the active organism of nitrification. 
We append, however, the following list of the principal contributions which have 
been made to our knowledge of the sulqect:— 
“Note on the Ferment-Theory of Nitrification.” F. H. Storer (‘Chem. Soc. 
Journ.,’ Abst., 1878, p. 932); in this it is shown that ammoniacal salts undergo 
nitrification in contact with peat, if air, filtered through cotton wool, is drawn through 
the mixture, whilst if the same mixture is first sterilised by heat, then the current of 
filtered air fails to bring about any nitrification. 
“Nitrification,” E. W. Davy (‘Pharm. Journ. Trans.,’ [3], vol. 10, pp. 1-3; 
‘ Chem. Soc. Journ.,’ Abstr., 1879, p. 1047), discusses the formation of nitrates and 
nitrites in natural waters, and contends that light is not inimical to the change, which 
takes place very readily between 70° and 80° Fahr. It is further pointed out that, 
ill the presence of organic matter, nitrites are formed. 
Warington, in “Alterations in the Properties of the Nitric Ferment by Cultiva¬ 
tion” (‘Chemical News,’vol. 44, p. 217 ; ‘Chem. Soc. Journ.,’Abst., 1882, p. 79), 
states that when ammoniacal solutions are seeded from old nitrifying solutions only 
nitrites and no nitrates are formed, and he attributes this phenomenon to diminished 
energy of the nitrifying organism. 
In a subsequent paper entitled “ Nitrification, Part III.” (‘ Chem. Soc. Journ.,’ 1884, 
p. 637), Warington describes a very extensive series of experiments, throwing light 
upon the special conditions which further nitrification. 
PiCHARU. in “ Comparative Nitrifying Effect of Various Salts ” (‘ Compt. Rend., 
vol. 98, p. 1289 ; ‘Chem. Soc. Journ.’, Abst., 1884, p. 924) shows that the presence of 
calcium sulphate greatly promotes nitrification, and institutes a comparison between 
the relative effect produced by the following salts ; thus— 
