FOUND BY THE ARCTIC VOYAGERS. 31 
wood, as 4gyrium rufum, A. atro-virens, Spheronema colliculosum, etc.; 
but whether the bleaching is caused by the Fungi, or whether they grow 
on wood already bleached, I am unable to say, as the kinds in ques- 
tion are not found in our lower latitudes. As far as I can judge from 
specimens, I am inclined to think that different species grow under very 
different conditions of the wood. 
In such as are before me I perceive the same difference in the degree 
of bleaching in the same spot, which I have before alluded to without 
being able to throw any light upon the subject. I had hoped by means 
of chemical agents to detect some difference of chemical condition, but 
have failed to do so. In all cases of bleached fibre, where decomposi- 
tion has not actually attacked the primitive walls of the cells, which 
consist of matter insoluble in water, the application of iodine and sul- 
phurie acid gives a more or less decided tinge of violet, and where the 
wood has been exposed to the wash of salt water, the tint assumed is 
much darker.. In woody fibre reduced to the state commonly known 
under the name of touchwood, it is well known that the walls do not 
remain in the state of cellulose, but approximate in their characters to 
bassorin; the fibres in that condition are however no longer in the 
state to which the term leached can properly be applied. In the case 
of surfaces where the subjacent wood is not affected, it is clear that the 
rain will constantly wash off the more tender or disintegrated portions, 
and the whited walls which still remain will therefore, to a greater or 
less degree, exhibit much the same chemical conditions as ordinary 
bleached fibre. ! 
There is à circumstance about the piece of Arctic Elm which has 
somewhat puzzled me. It exhibits three kinds of surface,—one which 
has been planed and painted with pitch or some similar material, one 
merely roughly sawed, and the split surface. On the smooth side 
little change comparatively has taken place; the fibres of the split sur- 
face are completely bleached, and many of them full of mycelium, but 
in other respects in the ordinary condition of such tissue in Elm; but 
on the sawed surface, where the ends of the fibres form a sort of velvety 
pile, the cells exhibit in various parts swellings of different kinds, as 
represented in the subjoined figure,—appearances which I have not been 
able to find in other parts of the wood, or in Elm or other wood which 
has been exposed to bleaching here (with the exception only of Larch), 
whether simply from weather, from the attacks of insects, or from the 
