146 
Arsenic  in  Glycerin. 
vnt  .lour.  Pharm. 
March.  1894. 
gm.  crystallized  bismuth  nitrate  and  3-5  gm.  gallic  acid  ;  the  pro- 
duct has  a  lemon-yellow  color,  is  free  from  nitrates  and  other 
impurities,  and  is  soluble  without  residue  in  sodium  hydrate  solution ; 
free  gallic  acid  cannot  be  detected  by  treatment  with  alcohol  or 
nitrate  by  extracting  with  boiling  water ;  the  formula  is  Bi(OH)2 
C7H505  when  dried  at  60-700  C. — B.  Fischer  and  B.  Griitzner* 
Arch,  der  Pharm.,  1893,  680  and  685. 
ARSENIC  IN  GLYCERIN.1 
By  Dr.  B.  H.  Paul  and  A.  J.  Cownley. 
The  presence  of  arsenic  in  glycerin  has  been  on  several  occasions 
a  source  of  alarm,  and  the  probability  that  the  method  of  manufac- 
ture adopted  in  the  production  of  glycerin  may  in  some  instance 
give  rise  to  impregnation  with  more  or  less  arsenic  is  sufficient  to 
give  importance  to  the  subject.  Quite  recently  it  has  been  stated 
by  Mr.  Fairley,  the  public  analyst  for  Leeds,  that  he  has  found 
appreciable  amounts  of  arsenic  in  the  glycerin  of  commerce.  We 
have,  therefore,  obtained  several  samples  of  glycerin  and  examined 
them  for  arsenic,  with  the  results  stated  in  the  accompanying  table: 
Sample 
Number. 
Result  of  test  applied  to 
the  Glycerin  (i  cc.)  direct. 
Result  of  Test  applied  after 
destroying  Sulphur  com- 
pounds by  Iodine. 
Stain  in  10  mins. 
Stain  in  16  hours. 
Stain  in  16  hours. 
No  stain  in  16  hours. 
Slight  stain  in  16  hours. 
Slight  stain  in  1  \  hours. 
Slight  stain  in  \\  hours. 
Stain  in  30  mins. 
Stain  as  before. 
Stain  as  before. 
No  stain  in  16  hours. 
No  stain  in  16  hours. 
Slight  stain  in  16  hours. 
Slight  stain  in  16  hours. 
Stain  as  before. 
Fraction  of  a 
milligramme 
of  Metallic 
Arsenic  in  i 
cc.  of  G 1  y- 
cerin. 
•OOI 
•OOI 
"OI 
The  samples  examined  were  less  numerous  than  we  intended, 
owing  to  some  promised  supplies  not  having  been  received,  but 
those  above  referred  to  represent  the  produce  of  several  makers,  and 
it  will  be  seen  that,  with  the  exception  of  No.  1,  the  amount  of 
arsenic  was  never  sufficient  to  be  a  cause  of  apprehension,  while  in 
three  of  the  eight  samples  there  was  no  indication  of  the  presence 
1  Phar.  Jour.  Trans.,  Feb.  24,  1894. 
