340  NOTES  ON  PRESCRIBING. 
where  provision  is  made  for  the  escape  and  subsequent  collec- 
tion of  the  large  quantity  of  fossil  ammonia,  which  is  always  pre- 
sent in  the  crude  acid.  The  whole  process  then  is  similar  to  the 
preparation  of  sal  soda  from  cake.  The  oxide  of  iron  which  the 
concentrated  solution  holds  in  suspension  is  removed  by  the  ad- 
dition of  a  minute  quantity  of  sulphuret  of  calcium  cake,  left 
from  the  extraction  of  crude  soda.  A  sulphuret  of  iron  forms, 
and  also  a  voluminous  precipitate  of  lime,  which  latter  envelopes 
the  iron  compound  and  carries  it  to  the  bottom.  This  renders 
the  solution  somewhat  alkaline. 
Hayesite  or  Boronatrocalcite,  from  Chili,  which  occurs  together 
with  Chili  nitre,  and  is  a  mixture  of  soda  and  lime-borate  with 
up  to  38  per  cent,  of  water,  the  outer  portions  being  often  mixed 
with  considerable  quantities  of  gypsum,  salt,  etc.,  but  even  the 
best  varying  from  12  to  50  per  cent,  in  boracic  acid.  Owing  to 
the  variability  of  its  richness  in  that  acid,  the  mineral  is  neg- 
lected as  a  source  for  borax,  the  more  so  since  both  the  Chilian 
mineral  and  the  Tuscan  product  are  monopolized  by  one  in- 
terest.— Druggists  Circular,  February,  1867. 
NOTES  ON  PRESCRIBING. 
By  Daniel  Hanbury. 
Although  more  than  fifty  years  have  elapsed  since  the  learned 
Dy.  Paris  placed  before  the  medical  profession  his  observations 
on  the  theory  and  art  of  medicinal  combination,  it  may  safely 
,be  asserted  that  nothing  has  been  since  written  on  the  same  sub- 
ject more  replete  with  sound  and  accurate  information. 
Yet  every  year  adds  to  our  experience:  not  only  are  new 
drugs  introduced,  but  new  combinations  and  new  forms  of  admin- 
istration are  also  adopted ;  and  the  prescriptions  of  the  present 
day  differ  as  much  in  character  from  those  that  found  their  way 
to  the  druggist's  counter  half  a  century  ago,  as  do  the  medicines 
then  in  vogue  from  those  which  are  now  in  use. 
The  art  of  prescribing,  it  must  be  admitted,  is  not  a  subject 
coming  precisely  within  the  province  of  the  pharmaceutist,  yet 
the  pharmaceutist  is  necessarily  acquainted  with  the  methods  of 
prescribing  which  are  prevalent  and  is  more  capable  than  any 
