theirs as we have throw light upon the state of
medical knowledge in their day. Thus there is extant a treatise on
_Materia Medica_ (1459); written by Cormac MacDuinntsleibhe
(Dunleavy), hereditary physician to the clan of O'Donnell in Ulster.
A more interesting work is the _Cursus Medicus_, consisting of six
books on Physiology, three on Pathology, and four on Semeiotica,
written in the reign of Charles I. of England by Nial O'Glacan, born
in Donegal, and at one time physician to the king of France.

O'Glacan's name introduces us to the middle period, if indeed it does
not belong there. _Inter arma silent leges_, and it may be added,
scientific work. The troublous state of Ireland for many long years
fully explains the absence of men of science in any abundance until
the end of the eighteenth century. Still there are three names which
can never be forgotten, belonging to the period in question. Sir Hans
Sloane was born at Killileagh, in Ulster, in 1660. He studied
medicine abroad, went to London where he settled, and was made a
Fellow of the Royal Society. He published a work on the West Indies,
but his claim to undying memory is the fact that it was the bequest
of his most valuable and extensive collections to the nation which
was the beginning and foundation of the British Museum, perhaps the
most celebrated institution of its kind in the world. Sloane's
collection, it should be added, contained an immense number of
valuable books and manuscripts, as well as of objects more usually
associated with the idea of a museum. He died in 1753.

The Hon. Robert Boyle was born at Lismore, in the county Waterford,
in 1627, being the fourteenth child of the first Earl of Cork. On his
tombstone he is described as "The Father of Chemistry and the Uncle
of the Earl of Cork", and, indeed, in his _Skyptical Chimist_ (1661),
he assailed, and for the time overthrew, the idea of the alchemists
that there was a _materia prima_, asserting as he did that theory of
chemical "elements" which held good until the discoveries in
connection with radium led to a modification in chemical teaching.
This may be said of Boyle, that his writings profoundly modified
scientific opinion, and his name will always stand in the forefront
amongst those of chemists. He made important improvements in the
air-pump, was one of the earliest Fellows of the Royal Society, and
founded the "Boyle Lectures." He died in 1691.

Sir Thomas Molyneux was born in Dublin