Am.  Jour.  Pharm.  \ 
February,  1902.  J 
Seidlitz  Powders. 
TARTARIC  ACID. 
79 
No. 
Weight  in 
Grammes. 
Qualitative  Tests. 
Estimation. 
i 
2 
3 
4 
5 
6 
U.S.P. 
2"I02 
2-30S 
2-679 
2-673 
2*253 
2-308 
2-250 
Traces  of  lead  and  sulphates. 
Sulphates  and  traces  of  calcium. 
Sulphates. 
CiiltVli  otpc  trafpc  oflparl  q  *n  H  r*a1r*intn 
OUi  JJJJ  dLC5,  Li                \JL  ltdU  aliU  LalLlulil, 
Traces  of  lead  and  sulphates. 
Sulphate  and  trace  of  lead. 
99-66 
100*07 
99-18 
99-98 
100-04 
Comments. — The  tartaric  acid,  as  is  seen  by  the  table,  is  almost 
uniformly  of  good  quality. 
The  weights  of  the  Seidlitz  mixture  show  quite  a  little  careless- 
ness in  weighing  or  measuring,  and  the  results  of  analysis  show  that 
there  is  also  considerable  carelessness  in  making  up  Seidlitz  mixture. 
Numbers  3  and  4  especially  show  this.  It  will  be  noticed,  by  adding 
up  the  percentages  in  numbers  3  and  5,  that  they  are  quite  a  little 
low.  These  samples  both  showed  tests  for  chlorides,  which  were, 
however,  found  to  amount  to  but  a  small  fraction  of  a  per  cent.  It  was 
noticed  that  these  samples  were  particularly  caked,  indicating  that 
the  low  percentage  might  possibly  be  due  to  adhering  moisture. 
They,  together  with  a  portion  of  CP.  Seidlitz  mixture,  were  then 
dried  at  ioo°  with  the  following  results  : 
CP.    sample,  loss  =  18-805  Per  cent. 
No.  3.     "  ,      "   —  20-048  " 
No.  5.     "        "  =  21-735  " 
It  is  observed  that  the  loss  in  number  3  is  1-243  Per  cent,  more 
than  the  CP.,  and  in  number  5  is  2-93  per  cent.  more.  This  does 
not  quite  account  for  the  entire  shortage,  but  it  is  enough  to  show 
that  it  is  in  all  probability  the  cause. 
To  verify  this  conclusion  a  portion  of  CP.  Seidlitz  mixture  was 
triturated  in  a  mortar  with  a  quantity  of  water  equivalent  to  the 
shortage  in  per  cent.,  and  to  all  appearances  it  remained  a  dry 
powder,  caking  when  wrapped  up  and  laid  away. 
Upon  examination  of  the  work  and  results  just  set  forth  it  will 
be  seen  that  for  all  practical  purposes  the  Rochelle  salt  might  be 
obtained  by  difference  between  the  entire  weight  taken  and  the 
