450 
THE  PREPARATIONS  OF  CONIUM,  ETC. 
means  of  rectifying  the  same  is  to  coat  the  picture  with  a  sizing 
solution,  glaze  it,  touch  out  the  spots  with  a  brush,  and  then  re- 
varnish  it.  With.  ■  albumenized  paper  of  ordinary  quality  the 
formation  of  these  spots  very  rarely  takes  place,  the  coating  of 
albumen  being  sufficient  to  resist  the  penetration  of  the  varnish. 
For  paintings,  either  in  oil  or  water  colors,  this  varnish  will 
be  found  suitable,  provided  aniline  colors  have  not  been  used. 
When  these  latter  colors  have  been  employed,  it  is  better  to  use 
dammar  or  mastic  varnish  made  by  dissolving  gum  dammar  or 
gum  mastic  in  oil  of  turpentine,  although,  on  account  of  its  soft 
and  sticky  character  and  its  liability  to  become  yellow,  I  can 
scarcely  recommend  it. 
My  spirit  varnish  answers  exceedingly  well  for  coating  nega- 
tives, and  may  be  applied  to  them  when  quite  cold.  If  it  does 
not  dry  with  sufficient  rapidity,  the  negative  may  be  warmed, 
but  this  is  by  no  means  necessary,  and  the  varnish  is  to  be  di- 
luted with  alcohol  if  such  a  proceeding,  is  adopted.— Druggist's 
Circular,  July,  1867. 
THE    PREPARATIONS    OF   CONIUM    OF  THE  BRITISH 
PHARMACOPCEIA,  1864  and  1867. 
By  John  Harley,  M.  D.,  Lond.,  F.  L.  S. 
(Assistant  Physician  to  King's  College  Hospital,  and  to  the  London  Fever 
Hospital,  etc.) 
(Continued  from  p.  3G7.) 
Uxtractum  Conii. — Having  completed  my  examination  of  the 
tinctures  and  succus,  I  come  now  to  the  consideration  of  the  ex- 
tract. Very  few  medicines  have  attained  so  great  a  reputation 
and  have  been  so  extensively  employed  as  the  extract  of  hem- 
lock. 
Introduced  by  Storck,  in  the  year  1761,  as  a  remedy  of  mar- 
vellous power  in  the  removal  of  almost  every  inveterate  disease 
to  which  the  human  frame  is  subject,  it  soon  obtained  admission 
into  the  Pharmacopoeias  ;  and,  regarded  as  it  is  by  practitioners 
of  the  present  day  as  a  powerful  and  useful  remedy,  it  is  still 
retained  in  almost  every  one  of  them.  I  myself  have  seen  it 
prescribed  almost  daily,  in  doses  varying  from  1  to  5  grains,  for 
the  last  twenty  years.    Nevertheless,  it  is  to  be  observed  that 
