GRANULAR  SALT  OF  CITRATE  OF  MAGNESIA.  231 
extracting  the  large  quantity  of  pectin  and  other  objectionable 
inert  principles  which  are  taken  up  when  a  No,  50  is  used.  And 
in  order  to  compensate  for  this  increased  coarseness  of  the  pow- 
der, I  have  directed  a  short  preliminary  maceration  and  very  close 
packing  of  the  powder  and  consequently  slow  percolation,  which 
ensures  the  thorough  exhaustion  of  the  drug. 
In  percolating  seneka  in  moderately  fine  powder  (No.  50,)  in 
making  this  syrup,  even  with  a  menstruum  consisting  of  two  parts 
of  alcohol  and  one  part  of  water,  I  have  upon  several  occasions 
found  the  concentrated  tincture,  when  cool,  to  become  of  jelly- 
like consistence,  almost  solid,  rendering  filtration  utterly  impos- 
sible. But  when  a  No.  30  powder  is  employed  all  that  difiiculty 
is  avoided,  the  tincture  is  quickly  filtered,  all  the  usual  impedi- 
ments attending  the  manufacture  of  the  syrup  are  removed,  and 
the  process  becomes  simple  and  easy  of  execution. 
The  syrup  as  made  in  accordance  with  the  above  formula  is  of 
reddish  brown  color,  perfectly  transparent,  permanent  and  de- 
posits but  little  if  any  upon  standing.  A  sample  of  it  made  last 
summer  is  now  in  excellent  condition,  with  no  deposit,  and  as 
transparent  as  when  freshly  made.  Another  sample,  made  about 
four  months  ago,  in  which  the  sugar  was  dissolved  by  means  of 
heat,  is  also  in  good  condition  with  the  exception  that  it  contains 
a  slight  gelatinous  deposit,  which  a  strong  heat  serves  to  have 
the  tendency  to  produce  after  the  syrup  has  stood  for  some  time. 
The  directions  given  in  the  above  formula  are  such  that,  if 
strictly  carried  out,  will  not  only  prevent  the  result  just  men- 
tioned, but  will  also  shield  the  medicinal  properties  of  the  seneka 
from  the  injurious  influence  which  a  high  degree  of  heat  undoubt- 
edly exerts  upon  them,  and  which  should  always  be  averted,  when 
practicable,  in  all  the  preparations  of  this  drug. 
Fhilada.,  April,  1870. 
REMARKS  ON  THE  GRANULAR   SALT   OF  CITRATE  OF 
MAGNESIA. 
By  H.  C.  Archibald. 
Of  late  years  the  demand  for  granular  prepared  citrate  of 
magnesia,  manufactured  by  the  firm  of  Charles  Ellis,  Son  &  Co., 
of  this  city,  has  increased  to  such  an  extent  as  to  make  it  now 
