e leaves in salad, but hardly of that species--_Ruta
montana_--which botanists say it is dangerous to handle without gloves.
Our garden species is _Ruta graveolens_ and is used by the French
perfumers in the manufacture of 'Thieves Vinegar,' or 'Marseilles
Vinegar,' once accounted an effective protection against fevers and all
infectious diseases.

A curious instance of the value of the herb in this respect occurred in
1760. In the summer of that year a rumour arose, and rapidly spread in
London, that the plague had broken out in St. Thomas's Hospital.
Immediately there was what would nowadays be called a 'boom' in rue, the
price of which rose forty per cent. in a single day in Covent Garden. To
allay the popular alarm a manifesto was issued, signed by the
physicians, surgeons, and apothecaries of the hospital, certifying that
there were no other than the 'usual' diseases among the patients in the
wards.

Another explanation of the origin of the name 'herb of grace' has been
given than that referred to above. Warburton, among others, thinks that
the name was adopted because the old Romanists used the plant on Sundays
in their 'exorcisms.' However this may be, rue, or the herb of grace,
has been in this country long accounted an antidote of witchcraft. But
then, so it was in the days of Aristotle, before it became 'herb of
grace,' and when it was hung round the neck as an amulet. The fact is,
however, that rue became an antidote of witchcraft because it had become
a noted implement in enchantment.

Through its numerous reputed properties, rue early found its way into
the magic cauldron.

'Then sprinkles she the juice of rue,
With nine drops of the midnight dew,
From lunary distilling,'

as Drayton has it. In this incantation, again, we have the association
with moonwort; and the connection is further illustrated in an old
oracle ascribed to Hecate: 'From a root of wild rue fashion and polish a
statue; adorn it with household lizards; grind myrrh, gum, and
frankincense with the same reptiles, and let the mixture stand in the
air during the waning of a moon; then address your words.'

With regard to the association with moonwort, it is interesting to
recall that this is one of the plants supposed to be employed by birds
for opening nests and removing impediments. Thus in an anecdote gravely
related to Aubrey, we find this virtue mentioned: 'Sir Bennet Hoskins
told me that his keeper at his parke at Morehampto