illustrations of the light and shade of foreground leaves belonging to the
nobler groups of thistles, because I thought they had been neglected by
ordinary botanical draughtsmen; not knowing at that time either the
original drawings at Oxford for the 'Flora Græca,' or the nobly engraved
plates executed in the close of the last century for the 'Flora Danica' and
'Flora Londinensis.' The latter is in the most difficult portraiture of the
larger plants, even the more wonderful of the two; and had I seen the
miracles of skill, patience, and faithful study which are collected in the
first and second volumes, published in 1777 and 1798, I believe my own work
would never have been undertaken.[29] Such as it is, however, I may still,
health being granted me, persevere in it; for my own leaf and branch
studies express conditions of shade which even these most exquisite
botanical plates ignore; and exemplify uses of the pen and pencil which
cannot be learned from the inimitable fineness of line engraving. The
frontispiece to this number, for instance, (a seeding head of the commonest
field-thistle of our London suburbs,) copied with a steel pen on smooth
grey paper, and the drawing softly touched with white on the nearer thorns,
may well surpass the effect of the plate.

23. In the following number of 'Proserpina' I have been tempted to follow,
with more minute notice than usual, the 'conditions of adversity' which, as
they fret the thistle tribe into jagged malice, have humbled the beauty of
the great domestic group of the Vestals into confused likenesses of the
Dragonweed and Nettle: but I feel every hour more and more the necessity of
separating the treatment of subjects in 'Proserpina' from the microscopic
curiosities of recent botanic illustration, nor shall this work close, if
my strength hold, without fulfilling in some sort, the effort begun long
ago in 'Modern Painters,' to interpret the grace of the larger blossoming
trees, and the mysteries of leafy form which clothe the Swiss precipice
with gentleness, and colour with softest azure the rich horizons of England