Am.  Jour.  Pharm. 
July,  1921. 
Book  Reviews. 
519 
Josiah  C.  Peacock  Elected  President  of  Pennsylvania 
Pharmaceutical  Association. — Josiah  C.  Peacock,  of  Philadelphia, 
was  the  unanimous  choice  for  president,  while  Buena  Vista  Spring 
was  chosen  after  a  friendly*  contest  as  the  place  for  holding  the 
forty-fifth  annual  meeting,  June  20,  21  and  22,  1922. 
President  Peacock  is  a  member  of  the  Class  of  '91,  Philadelphia 
College  pf  Pharacy  and  Science,  a  trustee  of  that  institution,  and 
is  chairman  of  the  Centennial  Committee  on  College  Membership. 
BOOK  REVIEWS 
"Chemical  Reactions  and  Their  Equations."  By  Ingo  W.  D. 
Hackh.  Ph.  C,  A.  B.,  Professor  of  Biochemistry,  College  of 
Physicians  and  Surgeons,  San  Francisco.  P.  Blakiston's  Son  & 
Company,  Philadelphia;  138  pages  $1.75  net. 
The  object  of  this  book  is  "to  supply  students  with  necessary 
material  and  to  expound  the  general  principles  of  balancing  equa- 
tions," the  author  having  observed  that  "the  inability  to  balance  a 
chemical  equation  is  a  most  common  difficulty  of  students  of  chem- 
istry. It  does  not  enter  into  a  detailed  discussion  of  physico-chem- 
cal  equations,  but  confines  itself  to  a  consideration  of  purely 
chemical  equations  from  a  technical  and  arithmetical  standpoint." 
Chapter  I  deals  with  Symbols  and  their  use  in  expressing  atoms, 
molecules  and  ions;  Chapter  II  with  Formulas  of  various  kinds 
(empirical,  rational,  etc.),  Valence  and  Valence  Numbers,  Oxida- 
tion and  Reduction ;  Chapter  III  with  Equations  involving  no  Oxida- 
tion and  Reduction ;  Chapter  IV  with  Equations  involving  Oxidation 
and  Reduction ;  Chapter  V  with  Reactions  and  their  Control ;  Chap- 
ter VI  with  Types  of  Chemical  Reactions  and  Equations. 
Reactions  are  illustrated  with  both  molecular  and  ionic  equa- 
tions, and  the  methods  used  in  balancing  them.  Under  Control  are 
considered  the  influence  of  temperature,  surface,  catalysts,  concen- 
tration, etc.  Each  chapter  closes  with  a  rather  comprehensive  set  of 
questions  and  problems  bearing  upon  or  illustrating  the  matter  there- 
in, adding  materially  to  the  value  of  the  book  as  a  'Student's  com- 
panion. 
