SECTION XXIII. In the two succeeding sections of this work, devoted
respectively to the examination of the Gothic and Renaissance buildings
in Venice, I have endeavored to analyze and state, as briefly as
possible, the true nature of each school,--first in Spirit, then in
Form. I wished to have given a similar analysis, in this section, of the
nature of Byzantine architecture; but could not make my statements
general, because I have never seen this kind of building on its native
soil. Nevertheless, in the following sketch of the principles
exemplified in St. Mark's, I believe that most of the leading features
and motives of the style will be found clearly enough distinguished to
enable the reader to judge of it with tolerable fairness, as compared
with the better known systems of European architecture in the middle
ages.

SECTION XXIV. Now the first broad characteristic of the building, and
the root nearly of every other important peculiarity in it, is its
confessed _incrustation_. It is the purest example in Italy of the
great school of architecture in which the ruling principle is the
incrustation of brick with more precious materials; and it is necessary
before we proceed to criticise any one of its arrangements, that the
reader should carefully consider the principles which are likely to have
influenced, or might legitimately influence, the architects of such a
school, as distinguished from those whose designs are to be executed in
massive materials.

It is true, that among different nations, and at different times, we may
find examples of every sort and degree of incrustation, from the mere
setting of the larger and more compact stones by preference at the
outside of the wall, to the miserable construction of that modern brick
cornice, with its coating of cement, which, but the other day, in