origin of the emulsion round the colonies, for a substance which is 
evidently insoluble in the agarplate, can only be found at the place 
where it is produced. This substance having in our case the nature 
of a plant slime, the enzyme may be called viscosaccharase. 
The enzyme is prepared by filtering a culture of B. mesentericus 
vulgatus and precipitating the filtrate with alcohol, whereby, of course, 
other enzymes formed by this bacterium such as diastase, and 
also the slime substance itself, are precipitated. Whether to the enzymes, 
present in this mixture mvertase must be reckoned, which is usually 
considered as a secretion-product of B. mesentericus, has become 
doubtful by the discovery of the viscosaccharase, at whose action, 
as will be seen below, together with the slime, the production of a 
reducing sugar is stated. 
Even in presence of chloroform the emulsion reaction takes rise 
on cane-sugar agar-plates through the enzyme produced from the 
mesentericus cultures, without anything being perceived of the develop¬ 
ment of the germs of B. mesmtericus itself, which may be still 
present after filtering and precipitating. 
It is not difficult to prepare plates of any size containing the 
emulsion everywhere, and fit for experiments to demonstrate by 
what influences it may disappear. 
To this end the required culture-agar is mixed before solidifying 
with a not too large number of germs, for example of B. emidsionis, 
and then placed one or two days in the thermostat; when the plate 
becomes quite turbid by the emulsion, the sugar is washed out 
and it is ready for the experiment. A drop of dilute acid thereon 
rapidly produces a clear space. 
At the action of viscosaccharase, besides the slime a 
redwing sugar is found. 
When small pieces of agar containing the emulsion are introduced 
into an experiment-tube and cautiously warmed with a little Fehling’s 
copper solution, a strong reduction is seen, which does not take rise 
with the same sugar-agar if the emulsion is wanting 
The question arose whether this reaction should be ascribed to 
t e slime itself, 01 it at the same time, through the viscosaccharase, 
or in another way, some other reducing substance is formed. There¬ 
fore small pieces of the agar containing the emulsion were washed out 
with water, whereby the slime, which cannot diffuse from the agar 
into the water remains behind, but the reducing power of the agar 
is lost, whilst the water used for the washing becomes itself strongly 
