44 
Reviews. 
( Am.  Jour.  Pharm. 
\    January,  1899. 
In  condensing  the  subject-matter  of  Part  III  for  the  medical  student  the 
author  has  omitted  mention  of  some  processes  which  are  important  to  the 
pharmaceutical  student.  For  instance,  no  mention  is  made  of  the  official  and 
the  other  processes  used  on  a  large  scale  for  the  preparation  of  solution  of 
hydrogen  dioxide,  yet  a  knowledge  of  such  methods  is  essential  to  an  under- 
standing of  the  tests  of  purity  giv.en  by  the  United  States  Pharmacopoeia  for 
this  substance.  The  preparation  of  the  so-called  colorless  tincture  of  iodine  by 
means  of  ammonia  water  is  given  on  page  130,  but  no  reference  is  made  to  the 
use  of  sodium  thiosulphate,  which  is  as  frequently  employed  in  making  this 
preparation,  in  fact,  authorized  by  the  National  Formulary  in  conjunction 
with  ammonia  water.  We  believe  also  that  the  description  of  processes  is  in 
some  cases  too  abbreviated  for  the  information  of  the  pharmaceutical  student, 
who  should  be  taught  to  master  the  mechanical  requirements  as  well  as  the 
chemical  details  of  processes;  e.g.,  the  description  of  acidum  sulphurosum, 
United  States  Pharmacopoeia,  on  page  162,  comprises  no  instruction  for  the 
washing  of  the  sulphur  dioxide,  or  its  absorption  in  cold  water. 
Another  defect  of  the  book,  in  our  opinion,  is  the  inconsistency  of  the 
atomic  weights  used  ;  thus,  in  the  case  of  zinc  there  are  three  different  numbers 
employed  to  represent  this  value,  as  shown  on  pages  86,  270  and  273.  The  list  of 
atomic  weights  used  in  the  book  is  not  the  one  recognized  by  the  United 
States  Pharmacopoeia.  While  we  would  not  use  the  last,  nor  any  other, 
authority  as  a  chock  to  the  wheels  of  progress  in  deducing  the  correct  atomic 
weights,  not  in  any  other  department  of  investigation,  at  the  same  time,  we 
believe  the  student  would  be  less  confused  by  studying  the  same  numbers  for 
the  atomic  weights,  both  when  he  reads  his  general  chemistry,  and  when  he 
goes  to  the  laboratory  to  do  the  testing  of  the  United  States  Pharmacopoeia, 
with  its  official  volumetric  solutions,  the  strengths  of  which  are  based  upon 
the  atomic  weights  of  a  certain  list. 
There  is  another  matter  in  which  the  author  indulges  to  some  extent,  and  to 
which  we  must  call  attention.  It  is  the  frequent  use  of  the  nearest  whole 
number  instead  of  the  mixed  number,  which  is  supposed  to  represent  the 
atomic  weight  of  an  element.  This  practice  is  altogether  a  too  common  one 
among  authors  of  books  on  chemistry.  If  teachers  and  authors  actually 
believe  these  numbers  to  be  exact  values,  they  should  always  insist  on  the  use 
of  the  fraction,  and  not  take  the  responsibility  of  decreasing  or  increasing 
them,  simply  to  enable  a  student  to  remember  the  numbers,  or  to  shorten  a 
calculation  somewhat.  If  the  student  violates  his  sense  of  accuracy  by  altering 
the  atomic  weights  in  the  said  manner,  let  it  be  at  his  own  bidding. 
On  account  of  the  objections  cited  against  this  part  of  the  book,  we  cannot 
recommend  it  as  a  guide  to  the  pharmaceutical  student. 
We  note  a  typographical  error  on  page  444,  where  C  is  used  instead  of  Ca. 
Josiah  C.  Peacock. 
The  British  and  Colonial  Druggists'  Diary,  1899,  44  Bishopsgate  With- 
out, London,  B.C. 
This  is  the  fourteenth  annual  issue  of  the  British  and  Colonial  Druggists' 
Diary,  and  contains  matter  of  permanent  utility  for  reference.  Among  the  new 
features  of  this  year's  edition  are  a  list  of  "  Photographic  Formulae  "  and  an 
article  on  "  Electricity  as  a  Hobby."    The  work  will  serve  the  purpose  of  ref- 
