( 1069 ) 
With exclusion of air solutions of chinate are apt to come into 
fermentation, as was already observed by Löw, whereby carbonic 
acid, acetic acid and propionic acid are formed. Hydrogen was not 
found; the inferred microbes belong to <Aérobacter aërogenes and 
allied forms. 
2. Oxidation of Quercite to Pyrogallie acid by 
Pseudomonas aromatica. 
The knowledge that chinie acid derived from the hexamethylene 
ring (hexahydrotetraoxybenzoic acid) can so readily be converted by 
many microbes into an aromatic substance, easily demonstrated by 
the ferri-reaction, suggested the question if substances exist, related 
to chine acid, that behave similarly. 
This consideration induced to subject quercite to an investigation 
analogous to the foregoing, the structure of this substance being the 
hexamethylene ring, in which 5 atoms of hydrogen have been replaced 
by hydroxyl. It was proved that also here, under the influence of life, 
an aromatic substance is easily produced, but at the same time that 
addition of a ferrisalt to indicate that substance is superfluous ; 
further, that but one single species of microbes seems to exist, of 
which only some varieties possess the faculty to form that substance. 
A more precise investigation showed that here the chemical reaction 
proceeds quite correspondingly with the oxidation of chinic acid, 
but that the product is, after all probability, pyrogallic acid, evidently 
resulting thus: 
C,H,,0, + 0 =C,H,O, + 3 H,0 
Quercite Pyrogallol 
Here, too, only one atom of oxygen per molecule of quercite is 
used. It should be noticed that in these experiments a large portion 
of the quercite vanishes in another way, probably as carbonic acid 
and water. 
The microbes causing this conversion are very generally distributed 
in our surroundings, but although there occur among them a number 
of clearly distinct varieties, they all belong to one and the same 
species, namely that of the “aroma bacteria’, well known in milk 
and milk products and for the first time distinctly described by 
Micuna') as Pseudomonas aromatica. It is a polarmonociliate short 
rodlet, little motile in plate cultures, more so in broth. 
1) System der Bakterien, Bd. 2, p. 880, 1900; with fig. Bd. 1, Tab. J, fig. 8. 
This description is based on Bacillus crassus aromaticus TaraRorr. — Probable 
synonyms: B. aromaticus lactis Grummer, Centralbl. f. Bacteriol. 2te Abt, Bd. 8, 
70 
Proceedings Royal Acad. Amsterdam. Vol. XIIlL. 
