AMjfnUi,m3RM  }  Tinct.  and  Syr.  of  Orange  Peel,  etc.  19 
frigerating  mixture,  and  the  temperature  of  the  water  contained  in 
the  vessel  is  thereby  readily  lowered  to  —  2  or  to  —  3 :  this  having 
been  done,  the  vessel  is  removed  from  the  mixture,  and  the  thermom- 
eters to  be  graduated  are  placed  in  it,  with  a  small  piece  of  ice ;  here- 
by the  water  becomes  suddenly  frozen,  while  at  the  same  time  the 
temperature  rises  to  0°.  When  one  has  no  ice  at  hand,  and  in  order 
not  to  complicate  the  operation,  the  temperature  of  the  water  should 
be  brought  down  to  —  4°,  when,  by  giving  a  gentle  tap  with  a  glass 
rod  to  the  bottom  of  the  vessel,  the  phenomenon  of  congelation  of  the 
water  will  be  observed,  the  temperature  rising  to  the  true  0°  abso- 
lutely.   I  draw  from  the  foregoing  the  two  following  conclusions  : — 
1.  That  the  expression  of  melting  ice  does  not  exactly  indicate  the 
true  0°,  and  that  therefore  it  ought  not  to  be  the  basis  of  the  deter- 
mination of  that  point. 
2.  That  by  applying  the  term  of  terminus  of  congelation  it  is  quite 
possible  to  estimate  with  certainty  the  exact  point  which  separates 
liquid  water  from  ice,  and  that  point  is  the  true  0°,  which  should  be 
the  starting  point  of  the  graduation  of  the  thermometer  scale. — Revue 
Hebdomadaire  de  Chimie. — Qhem.  News,  1872,  Nov.  22. 
TINCTURE  AND  SYRUP  OF  ORANGE-PEEL,  AND  TINCTURE  OF 
QUININE. 
By  Charles  Symes,  Ph.  D. 
The  preparation  of  tincture  of  orange  from  fresh  peel  is  a  matter 
which  has  engaged  my  attention  more  or  less  during  the  last  twelve 
years,  and  some  few  remarks  on  the  observations  I  have  made  from 
time  to  time  might  not  be  out  of  place,  especially  as  very  vague  con- 
clusions appear  to  have  been  arrived  at  on  this  subject  at  the  last 
Pharmaceutical  meeting,  after  a  description  of  some  (to  my  mind)  un- 
satisfactory experiments  by  the  President. 
On  March  8th,  1868,  I  brought  the  subject  before  the  members  of 
the  Liverpool  .Chemists'  Association,  exhibiting  a  sample  of  the  pre- 
paration in  question,  and  advocating  its  general  adoption  (vide  Phar- 
maceutical Journal,  2d  series,  vol.  IX,  p.  522),  but  it  received  com- 
paratively little  attention,  and  it  was  overruled  by  Mr.  Shaw  (in  the 
chair)  that  the  inconvenience  of  being  unable  to  obtain  fresh  peel  at 
all  seasons  of  the  year  was  sufficient  to  justify  the  continuance  of  the 
process  according  to  the  B.  P. 
