No.  V.  in  this  collection  is  the  address :  '  De
Chemii  suos  errores  expurgante,'  which  he  de-
livered when  he  became  professor  of  chemistry  at
Leyden,  21  Septr. ,  1718,  and  in  which  he  shows
that  the  vagaries  of  the  alchemists,  the  theories  of
fermentation  and  effervescence,  the  fixing  and
weighing  of  fire,  the  acid  and  alkali  theory  in
physiology  and  medicine — all  the  errors  that  the
chemists  of  one  period  fell  into — have  been  corrected
by  the  subsequent  investigations  of  chemists  them-
selves.
Boerhaave  (1668-1738)  was  professor  of  medicine
and  botany  from  1709,  and  of  chemistry  from  1718,
at  the  university  of  Leyden.  He  was  the  most
distinguished  teacher  of  his  time,  and  a  man  of
immense  and  varied  learning  in  languages,  philo-
sophy, theology,  mathematics,  botany,  chemistry,

Stolle,  Anleitung  zur  Historic  der  Medicinischen
Gelahrheit,  1731,  passim.
Kestner,  Medicinisches  Gelehrten-Lexicon,  1740,
p.  122.
W.  Burton  :  An  account  of  the  Life  and  Writ-
ings of  H.  Boerhaave,  London,  1743 ;  2nd  edition,
1746.
Chaufepie,  Nouvelle  Dictionnaire  historique,
1750,  ii.  (letter  B),  pp.  337-355-

Eloy,  Dictionnaire  Historique  de  la  Medecine,

1755,  pp.  159-175 ;  1778,  i.  P.  37°-

A  new  and  general  Biographical  Dictionary,
1761,  ii.  p.  257.
Haller,  Bibliotheca  Botanica,  1772,  ii.  96.
Haller,  Bibliotheca  Anatomica,  1774,  i.  p.  756.
Haller,  Bibliotheca  Chirurgica,  1774,  i.  583.
Baumer,  Bibliotheca  Chemica,  1782,  p.  34.
Haller,  Bibl.  Medicines  practice,  1788,  iv.  p.  142
&  sqq.  The  whole  of  Lib.  xii.  has  Boerhaave's
name.
Weigel,  Einleitung  zur  allgemeinen  Scheidekunst ,
1788,  i.  p.  200.
De  Chalmot,  Biographisch  Woordenboeck  der
Nederlanden,  1798-1800;  iii.  pp.  205-30.
Hutchinson,  Biographia  Medica,  1799,  i.  pp.
82-101.
