Am.  Jour.  Pharm. ) 
November,  1920.  ) 
Book  Reviews. 
841 
Manager  of  their  Chicago  branch.  A  year  later,  he  was  made 
manager  which  position  he  has  since  occupied  up  to  his  election  as 
President.  In  this  position  he  demonstrated  exceptional  ability 
and  under  his  regime  the  business  has  trebled. 
Mr.  Peckham  is  a  young  man — under  forty-five — but  his  broad 
knowledge,  energy  and  years  of  experience  in  handling  the  affairs 
of  the  Company's  largest  branch  have  well  fitted  him  for  the  presi- 
dency of  this  prominent  pharmaceutical  industry. 
BOOK  REVIEWS. 
Margarine;.  By  William  Clayton,  M. Sc.  Longmans,  Green  &  Co., 
London.    187  pages,  cloth  bound.    Price,  $4.75. 
The  series  of  monographs  on  Industrial  Chemistry,  edited  by 
Sir  Edward  Thorpe,  has  been  added  to  by  the  publication  of  this 
excellent  work  on  Margarine,  the  first  of  its  kind  in  any  language 
according  to  the  author. 
The  work  includes  a  consideration  of  Oils  and  Fats  Used  in  Marga- 
rine Manufacture,  Edible  Hydrogenated  Oils,  Milk  Examination, 
Margarine  Manufacture,  Theory  of  Emulsification,  Butter  and 
Renovated  Butter,  Analysis  of  Butter  and  Margarine,  Deteriora- 
tion of  Butter  and  Margarine  in  Storage,  Nutritional  Chemistry  of 
Fats  and  Oils. 
The  book  is  illustrated  with  many  half-tone  plates  and  figures 
in  the  text  and  contains  a  complete  bibliography  of  the  subject 
occupying  thirty-five  pages  ir  the  appendix.  There  are  three 
separate  indexes,  one  for  authors,  one  for  patents  (American,  Eng- 
lish and  German),  and  a  very  complete  subject  index. 
The  book  as  a  whole  is  of  particular  interest  only  to  the  food 
chemist  or  food  law  enforcement  officer,  but  the  chapter  on  the 
theory  of  emulsification,  which  is  very  complete  and  up-to-date, 
makes  the  book  a  worth  while  addition  to  any  scientific  library. 
C.  H.  Law. 
The  De:termination  of  Hydroge:n  Ions.    By  W.  Mansfield  Clark, 
M.A.,  Ph.D.,  Chemist,  Research  Laboratories  of  the  Dairy  Divi- 
sion, United  States  Department  of  Agriculture.    8vo.,  309  pages 
and  index.    Williams  and  Wilkins,  Baltimore.  $5.00. 
The  theory  of  ionization  was  set  forth  by  Arrhenius  in  the  first 
volume  of  the  Zeitschrift  fuer  physikalische  Chemie,  in  1887.  As 
