takes nothing for granted, which, in reading a well-
arranged and instructive series of illustrations, argumentatively
applied, is continually asking, “ Quo
tramite tendis ?” And when, at length, the goal is
discovered to which Mr. Ellis is conducting it — when
he briefly concludes, “ Against the evils arising from
such a vitiated atmosphere, the plan of Mr. Ward
provides effectual protection, as the success of his
establishment amply demonstrates,” then this little
jury pronounces instantly a verdict of “ Not Proven.”
Mr. Ellis seems scarcely aware of the extreme ditfl-
culty of maintaining any essential difference between
the component parts of atmospheric air on the internal
or external side of any given partition. He seems
scarcely aware that Mr. Ward’s establishment—the
success of which he justly considers beyond dispute—
communicates with the surrounding murky and foul
atmosphere by means of a glass door, of the usual
construction—a door opened by every visitor on
entering this paradise—
“ Exiguus spatio, variis sed fertilis herbis ;”*
And again by every visitor on returning; and that
these openings are much too frequent to allow the
possibility of maintaining any difference in the proportions
of the gases composing the internal and external
air, even supposing that the air would not so far
elude Mr. Ward’s care, were the door rigidly kept shut,
as not to insinuate itself through the ten thousand
* This line, from the Moretum of Virgil, is over the door.
XXV
crevices, which every glass-house must possess.
Before assigning the excess of sulphurous and muriatic
acid gases as the deleterious property of atmosphere,
obviated by Mr. Ward’s plan, Mr. Ellis should
have shown us that this excess was so obviated. He
should have shown us that the deleterious gases did
not exist within; he should have tested the interior,
and given us the result; he should have told us by
what mystic character engraved on the threshold these
gases were scared away; in short, he should have
done what he has not done—he should have analyzed
facts rather than assumed them. The small inquiring
class, flnding that this important link in the chain of
argument is deflcient, will be apt to think that the
lapse of that single link sets adrift the entire cargo
of conclusions.
Having dismissed the gases with the alternative,
that either they do not exist in any undue proportion
in Mr. Ward’s fernery and its neighbourhood, or that
they do exist, and are not injurious to vegetation; having
seen also that fuliginous matter does exist in the
atmosphere to a great extent, that it is highly injurious
to the growth of vegetables, and that it is excluded
by Mr. Ward’s plan, we shall perhaps be expected,
without further inquiry, to conclude that in the
exclusion of fuliginous matter rests the whole secret
of its effect. To this I must demur, or the use of
these closed cases would be conflned to London and
similar smoky atmospheres; whereas it is well known
the sphere of their utility is universal. Every cultid
! '