but scarcely visible on pale ones.

The flash was frequently seen on the same flower two or three times in
quick succession, but more commonly at intervals of several minutes; and
when several flowers in the same place emitted their light together, it
could be observed at a considerable distance.

This phaenomenon was remarked in the months of July and August, at
sun-set, and for half an hour after, when the atmosphere was clear; but
after a rainy day, or when the air was loaded with vapours, nothing of it
was seen.

The following flowers emitted flashes, more or less vivid, in this
order:

1. The Marigold, _(Calendula Officinalis)_.
2. Garden Nasturtion, _(Tropaeolum majus)_.
3. Orange Lily, _(Lilium bulbiferum)_.
4. The Indian Pink, _(Tagetes patula et erecta)_.

Sometimes it was also observed on the Sun-flowers, _(Helianthus annuus)_.
But bright yellow, or flame colour, seemed in general necessary for the
production of this light; for it was never seen on the flowers of any
other colour.

To discover whether some little insects, or phosphoric worms, might not
be the cause of it, the flowers were carefully examined even with a
microscope, without any such being found.

From the rapidity of the flash, and other circumstances, it might be
conjectured, that there is something of electricity in this phaenomenon.
It is well known, that when the _pistil_ of a flower is impregnated, the
_pollen_ bursts away by its elasticity, with which electricity may be
combined. But M. Haggren, after having observed the slash from the
Orange-lily, the _anthers_ of which are a considerable space distant from
the _petals,_ found that the light proceeded from the _petals_ only;
whence he concludes, that this electric light is caused by the _pollen_,
which in flying off is scattered upon the _petals._ Obser. Physique par
M. Rozier, Vol. XXXIII. p. iii.

P. 153. _Addition to Avena._ The following lines were by mistake omitted;
they were designed to have been inserted after l. 102, p. 153.

Green swells the beech, the widening knots improve,
So spread the tender growths of culture'd love;
Wave follows wave, the letter'd lines decay,
So Love's soft forms neglected melt away.

P. 157. _Additional note to Bellis._ Du Halde gives an account of a white
wax made by small insects round the branches of a tree in China in great
quantity, which is there collect