130 Potter. — On the Occurrence of Cellulose in the 
sulphate showed the middle lamella of the wood-fibres a distinct yellow, 
but enclosing an inner layer remaining white and unstained. The walls 
of the wood-vessels and tracheides stained yellow. In the longitudinal 
sections the same peculiarities of staining were noted, but in the wood- 
vessels the borders of the pits remained unstained. Similar sections when 
stained with phenol showed the middle lamella of the wood-fibres green, 
but the inner layers of the walls white and unstained ; the wood-vessels 
and tracheides stained green. Again, in longitudinal section the borders of 
the pits were unstained. Phloroglucin stained precisely the same structures, 
and again the borders of the pits remained unstained. 
Similar investigations with Quercus , Alnus , and Ulmus gave the same 
results. Fig. 8, showing a transverse section of Quercus after steaming, 
depicts a stage in which the progressive action of the delignification may 
be observed. The violet colour given by chlor-zinc-iodine is seen staining 
deeply around the lumen, and suffusing itself gradually outwards into the 
lignified layers. 
The above experiments show that boiling water extracts some sub- 
stance of the nature of lignin from the wood of all these trees and that 
sterilization by steaming would have a similar effect. To determine this 
point further some sawdust was obtained from a piece of Aesculus 
(diameter 3-5 cm., annual rings 19), covered with distilled water, and 
steamed for half an hour on one afternoon and again for an equal time next 
morning. The sawdust was then removed by filtration through an ordinary 
filter paper. A small portion of the watery extract thus obtained reacted 
very feebly to phloroglucin, but the colour was sufficient to indicate that 
some substance was present which gave the lignin reactions. The remainder 
of the filtrate was next extracted with ether, the water drawn off with 
a separating funnel, and the ether evaporated in a small white crucible 
on a water bath at 6o° C. A brown deposit remained as a thin layer in 
the crucible after the ether had disappeared. This brown layer gave 
at once the characteristic red colour when a drop of phloroglucin was added. 
In order to avoid any risk of minute fragments of wood passing 
through the filter paper and hence into the ether, or by any chance some 
substance being extracted from the filter paper which might react to 
phloroglucin, a similar watery extract of Aesculus sawdust was passed 
through a Kitasato tube, extracted with ether, and the ether evaporated. 
The result on addition of a drop of phloroglucin to the residue was the 
same, the red colour was instantly given. It only remains to say that 
the ether and distilled water alone, after the same treatment, gave no brown 
deposit, and not the slightest reaction to phloroglucin. 
This shows conclusively that a substance which reacts to phloroglucin 
is extracted from Aesculus wood by boiling water, and confirms in a 
remarkable manner the reactions to the lignin and cellulose tests of the 
