( 798 ) 
As we had found that the slime at the bottom of the flask is less 
soluble than that obtained by alcohol from the emulsionated liquid 
above it, we prepared laevulan from this slime also by separate 
experiments, for we supposed that dextran might occur therein, which 
is much less soluble in water than laevulan. However, it was found 
that the laevulan obtained in this way gives no other rotation after 
inversion than the emulsion laevulan, from which it does not differ. 
Hence it is sure that hay bacteria produce no dextran at all, but 
that their cell-wall consists of various modifications -of laevulan of 
different solubility. 
Not only in media of the above composition B. mesentericus pro¬ 
duces laevulan, this happens quite as easily in a yeast decoction 
with 2 to 20% of cane sugar, addition of chalk proving favourable. 
The temperature of cultivation may also vary and even rise to 40° C., 
but then care should be taken that the laevulan itself be not attacked 
by the producer. 
From the preceding it may be concluded that the large lumps of slime 
so easily formed on cane sugar agar-plates by B. mesentericus and 
the other emulsionating species consist as well of laevulan as the 
emulsion which occurs round the colonies of this species in the agar. 
Hence, it can neither be doubted that the slime of these colonies, 
which does not diffuse in the agar, is produced by viscosaccharase 
from cane sugar, and that this enzyme only partly gets out of the 
bacterial body proper, the cell-wall included. Evidently in the cell- 
wall itself the enzyme forms new laevulan by converting the cane 
sugar, with which both cell-wall and agar-plate are imbibed. 
The production of cell-wall substance in consequence of the action 
of an enzyme, which in my former communication was called pro¬ 
bable, must now, as regards laevulan, be considered as proved. 
Dextran and the dextran bacteria, which we have likewise studied, 
shall later be treated more thoroughly. For the moment it may be 
observed that by this substance the polarised light is strongly rotated 
to the right; we found 
« D = + !**>, 
whilst in the literature by various authors is given for dextraq 
a D =-fl99° to 230°. 
Quite like laevulan it results exclusively from cane sugar. So lae¬ 
vulan as well as dextran are produced by microbes, neither from 
laevulose, glucose, or any other sugar, but solely from cane sugar 
and raffinose. The slimy cell-wall substances formed by other microbes 
from glucose, laevulose and maltose, are of a different nature. 
