Am.  Jour,  Pharm.  ) 
August,  1921.  ) 
Book  Reviews. 
borrowed)  are  of  too  poor  a  quality  to  occupy  the  positions  they 
hold. 
On  the  other  hand  the  simplicity  of  style  is  much  in  favor  of 
the  beginner  who  will  not  be  burdened  by  the  intricacies  of  so 
vast  and  difficult  a  field  as  botany.  The  author  has,  however,  in 
trying  to  reduce  facts  to  their  lowest  terms,  here  and  there  sacrificed 
comprehensive  understanding  for  brevity. 
At  the  present  time,  therefore,  it  seems  that  while  the  book  is 
not  as  valuable  as  some,  it  should,  nevertheless,  serve  as  a  nucleus 
for  greater  achievement. 
M.  S.  DUNN. 
"Analyst's  Laboratory  Companion."  By  Alfred  E.  Johnson, 
B.  Sc.  Lond.  Fifth  Edition.  P.  Blakiston's  Son  &  Co.,  Phila- 
delphia, publishers;  176  pages.    Price,  $3.50  net. 
This  book,  as  the  title  would  indicate,  is  intended  as  an  aid  to 
the  laboratory  worker.   In  this  edition  the  author  has  enlarged  upon 
and  revised  several  of  the  important  features  of  previous  editions 
and  presents  to  the  analyst  a  valuable  and  up-to-date  collection  of 
tables  and  data. 
When  one  considers  that  about  seventy  separate  headings  are 
listed  among  the  contents  of  this  little  volume  he  realizes  how  com- 
pact and  concise  a  book  of  this  size  must  be.  Practically  all  of  the 
more  important  and  useful  tables  that  are  required  in  laboratory 
routine  are  given.  Among  these  are  tables  of  the  international 
atomic  weights  for  1921,  logarithms,  densities  of  gases,  gravimetric 
and  volumetric  factors,  corrections  for  volumes  of  gases,  volume  and 
density  of  water  at  different  temperatures,  Baume's  hydrometers, 
strength  of  hydrochloric,  nitric  and  sulphuric  acids  of  different  densi- 
ties, tables  required  for  water  analysis,  for  phosphates,  for  the  con- 
version of  nitrogen  into  ammonia,  for  the  Kjeldahl  process,  thermo- 
metric  tables,  alcoholometric  tables  and  tables  of  constants  for  oils, 
fats  and  waxes.  There  are  also  useful  tables  on  freezing  mixtures, 
melting  points  of  metals,  reciprocals  of  numbers,  percentage  com- 
positions of  commonly  occurring  compounds  with  formulae  and 
molecular  weights,  densities  of  elements  and  common  substances, 
