•356 Proceedings of the Royal Physical Society. 
some relation to fact ; but without going into tbe history of 
this opinion, it will be enough to notice, that as far as I am 
aware there is but one place in Lewis where the remains of 
forest trees are to be found. The roots of firs over twelve 
inches in diameter occur near Balaline, in the parish of Lochs, 
and only there. These roots are always on the clay soil, for 
neither bush nor tree is found with its roots in the peat. 
But although in a thousand cases the section of a peat bank, 
from its surface to its base, exhibits only a succession of marsh 
plants, a patient observer will here and there find a spot 
where the foundation of the peat is a floor of twigs and leaves. 
This, as stated before, bears only a minute proportion to the 
moor peat of the country. When examined it appears to be 
made up in great part of the twigs of the birch, but I have no 
doubt that the berry and bush of the mountain ash, the larch, 
the aspen, and the willow could be detected. In fact, it so 
happens that in this strange country, where many of the 
manners of the tenth century still exist, the method by which 
this peat of scrub and brushwood was formed can still be 
seen. On the small islets in the lakes, to which neither 
sheep nor cattle can gain access, a dense mass of scrub still 
survives. The heather will grow four feet in height, and 
above that may be seen the red berries of the mountain ash, or, 
if in spring, the catkins of the willow, or the pendant leaves 
of the aspen, with briers and brambles to interlace the whole. 
In the face of some cliffs and banks, and even in a few re- 
mote spots, the holly, hazel, aspen, birch, and willow, still 
struggle against an adverse climate as they did a thousand 
years ago. 
I have been thus particular in pointing out the limited 
quantity of wood peat, and where it occurs, its position, rest- 
ing upon the boulder clay, for a purpose to be more particu- 
larly described at the close of this paper ; and I pass on to 
notice some important geological changes that have taken 
place in the most recent or peat-forming era. 
My official duties led me last summer over several hundred 
miles of the most tortuous coast-line imaginable. Between 
North and South Uist lies the large island of Benbecula, and 
about five hundred others of different sizes and shapes ; most 
