264 
Chemical  Notes, 
Am.  ^our.  Pharm. 
May,  1880. 
scale  as  to  its  use  as  a  means  of  extracting  the  perfunne  of  flowers. 
Using  this  solvent,  which  evaporates  at  very  low  temperature,  for 
extraction  in  closed  vessels,  the  perfumes  are  obtained  perfectly  unal- 
tered and  in  fresh  condition,  mixed  with  fat  and  wax  like  substances. 
This  mixture  gives  up  to  alcohol  the  perfume  perfectly  pure.  The 
methyl  chloride,  to  be  used  for  this  purpose,  must  be  previously  treated 
with  concentrated  sulphuric  acid,  to  free  it  from  traces  of  a  bad-smell- 
ing compound  which  may  sometimes  accompany  it. — Ibid^  Feb.,  1880, 
p.  59. 
0?i  the  Reaction  of  Ferric  Chloride  with  Salicylic^  Carbolic^  Gallic  and 
Tannic  Acids. — H.  Hager  gives  the  following  means  of  distinguishing 
between  these  acids  by  the  aid  of  the  ferric  chloride  test.  The  sub- 
stances which  interfere  with  the  violet  coloration  which  terric  chloride 
gives  with  these  acids  are  numerous,  and  by  noting  them  we  may 
obtain  a  clue  as  to  which  of  the  acids  may  be  present  in  a  solution. 
Thus  with  salicylic  acid  the  reaction  is  not  disturbed  or  hindered  by  the 
presence  of  acetic,  boracic,  sulphuric,  nitric  or  hydrochloric  acids  (all 
acids  in  dilute  condition),  common  salt,  nitre,  glycerin,  alcohol,  amyl 
alcohol  or  ether.  It  is  hindered  by  caustic  alkalies,  alkaline  carbon- 
ates, sodium  acetate,  ammonium  acetate,  borax,  potassium  iodide, 
sodium  phosphate,  oxalic,  citric,  tartaric,  phosphoric  and  arsenic  acids. 
With  carbolic  acid  the  reaction  is  not  hindered  by  boracic  acid,  common 
salt  or  potassium  nitrate.  It  is  hindered  by  acetic,  oxalic,  tartaric, 
citric,  sulphuric,  hydrochloric,  nitric  and  phosphoric  acids,  sodium  ace- 
tate, ammonium  acetate,  borax,  sodium  phosphate,  glycerin,  alcohol, 
amyl  alcohol  and  ether. 
Phosphoric  acid  decolorizes  both  with  salicylic  and  carbolic  acids 
and  with  gallotannic  and  gallic  acids  as  well.  The  officinal  sodium 
phosphate,  however,  hinders  the  reaction  with  salicylic  and  carbolic 
acids,  but  not  with  tannic  and  gallic  acids. 
For  a  preliminary  distinction  between  salicylic  and  carbolic  acids  the 
solution  is  to  be  treated  in  abundance  with  alcohol  or  glycerin,  or  with 
dilate  acetic  acid,  and  then  tested  with  ferric  chloride,  Salicylic  acid 
will  give  the  reaction,  carbolic  acid  will  not. 
To  distinguish  whether  gallotannic  or  gallic  acid  be  present,  add 
sodium  phosphate  to  the  solution,  and  then  test  with  ferric  chloride. 
The  violet  coloration  will  show  their  presence,  but  is  not  produced  by 
salicylic  or  carbolic  acids. — Dingier' s  Polytechn.  Jour.^  235,  p.  407. 
Note  on  the  Action  of  the  New  Diastase^  Eurotin^  on  Starch. — R.  W . 
