46 
COMMERCIAL  HYDRARGYRUM  CUM  CRETA. 
PERCENTAGE  OF 
SAMPLE. 
Metallic 
Mercury. 
Suboxide 
of  Merc. 
Oxide  of 
mercury. 
Sugar. 
1>  0    i . 
JF  rom 
8)  manuiaiCturer  in  Jrnilar. 
35-91 
0-008 
0-3*72 
none 
No.  2. 
a 
11              u                u  u 
35-01 
0-08 
0-465 
No.  3. 
dispensing  bottle  in  " 
L  (  o  i 
0-08 
14-2*73 
No.  4. 
"  manufacturer      "  " 
32-81 
0-01 
0-265 
No.  5. 
(f 
"  dispensing  bottle  "  " 
12-41 
0-11 
25-69 
No.  6. 
made 
in  England 
29-01 
0-03 
0-50 
No.  V. 
a 
by  succussion 
36-30 
none 
A  trace, 
a  trace 
producing 
brown  dis- 
coloration 
,  % 
on  addi- 
tion of  H.S. 
No.  8. 
From 
a  manufacturer  in  N.  Y. 
29.82 
0-01 
0-838 
none 
No.  9. 
"  dispensing  bottle  in  " 
30-32 
0.05 
1-416 
11 
It  will  be  noticed  that  two  samples  obtained  from  dispensing 
bottles  contained  respectively  14*2  per  cent,  and  25-6  per  cent, 
of  oxide  of  mercury.  As  the  quantity  of  mercury  originally 
present  could  not  have  been  more  than  37-5  per  cent.,  (the  offi- 
cinal quantity),  it  will  be  seen  that  over  one-third  of  the  mercury 
in  one,  and  nearly  two-thirds  in  the  other  had  been  oxidized. 
The  samples  obtaii||^d  from  the  manufacturers  contained,  in  com- 
parison, but  little  oxide,  and  from  this  it  is  inferred  that  the 
change  takes  place  in  the  dispensing  bottle.  An  expected  sam- 
ple of  Hydrargyrum  cum  Creta  made  by  Dr.  Stewart's  process 
was  not  received,  but  the  disappointment  was  rendered  lighter 
by  the  fact  that  a  sample  assayed  by  Prof.  Procter,  when  it  was 
only  eighteen  months  old,  gave  22-8  per  cent  of  oxide.  This 
process,  however,  is  seldom  if  ever  used.  Three  samples  of 
Hydrargyrum  cum  Creta  made  by  the  succussion  process  were 
taken,  soon  after  accepting  this  query,  for  the  following  experi- 
ment :  In  one,  the  powder  was  simply  wrapped  in  paper,  and 
the  package  allowed  to  lie  in  an  exposed  place,  with  access  to 
the  sun's  rays,  heat,  moisture,  &c.  Another  portion  was  put  in 
a  bottle  and  stopped  loosely  with  a  cork  stopper,  as  an  ordinary 
pharmacist  would  be  likely  to  keep  it.  A  third  was  put  in  a 
bottle  and  the  cork  sealed,  and  the  bottle  secluded  from  light* 
At  the  expiration  of  eleven  months  these  three  samples  were  ex- 
amined chemically,  and  with  the  aid  of  the  microscope,  and  no 
appreciable  difference  could  be  detected  ;  this  result  is  attributed 
to  the  protecting  influence  of  the  small  proportion  of  honey  left 
in  the  preparation. 
