378  Quantitative  Analysis  of  Zinc  Ointment,  j  Amiugu£'  i9v/m' 
tube  be  then  gently  agitated  so  as  to  slightly  but  not  entirely  mix  the  two 
layers  a  red  ring  or  zone  will  be  produced  at  the  point  of  contact  if  fur- 
furaldehyde  be  present,  indicating  the  presence  of  added  invert  sugar. 
Unfortunately  this  test  is  not  infallible,  for  when  pure  genuine 
honey  is  heated  (as,  for  instance,  in  the  process  of  clarification 
when  heat  is  sometimes  used),  furfuraldehyde  is  also  formed  and 
the  test  is  of  no  value  therefore  unless  applied  to  honey  which 
has  been  known  to  never  have  been  heated. 
In  conclusion  I  would  say  that  it  is  not  possible  to  detect  cane 
sugar  in  honey  in  the  sense  of  a  qualitative  test;  that,  as  cane  sugar 
is  normally  present  in  small  amounts,  its  quantitative  determination, 
preferably  by  means  of  the  polariscope,  becomes  necessary;  that 
the  form  in  which  sugar  is  added  usually  is  that  of  invert  sugar 
which  can  be  readily  detected  in  honey  which  has  never  been  sub- 
jected to  heat. 
A  RAPID  ACCURATE  METHOD  FOR  THE  QUANTITA- 
TIVE ANALYSIS  OF  ZINC  OINTMENT.1 
By  Joseph  L.  Mayer. 
In  testing  some  samples  of  Zinc  Oxide  Ointment  recently,  it 
appeared  to  me  that  the  analytical  methods  now  in  use  were  too 
involved  and  time-consuming  for  the  pharmacist;  I  therefore  de- 
vised the  following  very  simple  and  accurate  process : 
Into  a  tared  porcelain  crucible  accurately  weigh  I  gramme  of 
the  sample,  heat  cautiously  until  the  material  bursts  into  flame, 
allow  to  burn  quietly  until  all  inflammable  material  is  consumed, 
then  heat  strongly  with  the  Bunsen  burner  until  all  organic  matter 
is  burned  off,  cool  and  weigh. 
Should  difficulty  be  experienced  in  burning  off  organic  matter, 
moisten  with  a  drop  of  nitric  acid,  heat  cautiously  to  avoid  spat- 
tering, and  then  with  the  full  flame  as  before. 
Since  I  gramme  of  the  sample  is  taken  the  residue  which  is 
oxide  of  zinc  can  easily  be  computed  into  percentage  by  multiply- 
ing the  result  by  one  hundred. 
Of  course,  if  necessary,  this  result  can  be  checked  by  deter- 
1  Read  before  the  New  York  State  Pharmaceutical  Association,  June, 
1913. 
