312 
Reviews. 
Am.  Jour.  Phar.m 
June,  1894. 
author  of  this  interesting  and  beautiful  volume.  It  is  made  up  of  (i)  Reports 
of  the  Officers  and  Director;  (2)  Anniversary  Publications;  (3)  Scientific 
Papers.  The  last  show  considerable  care  and  original  research  on  the  part  of 
the  authors.  Three  of  the  papers  are  of  especial  interest  and  value,  viz.:  " A 
Study  of  the  Venation  of  the  Species  of  Salix  described  in  Gray's  Manual, 
with  Reference  to  their  Determination,"  by  Dr.  N.  M.  Glatfelter.  "  Material 
for  a  Monograph  on  the  Tannoids,  with  Special  Reference  to  Vegetable 
Physiology,"  by  J.  Christian  Bay,  and  "The  Sugar  Maples,  with  a  Winter 
Synopsis  of  all  North  American  Maples,"  by  William  Trelease.  The  Report 
is  published  for  gratuitous  distribution  and  exchange  within  certain  limits,  but 
may  be  purchased  of  the  agents,  Dr.  A.  E.  Foote,  of  Philadelphia  ;  W.  Wesley 
&  Son,  of  Ivondon,  and  R.  Friedlander  &  Son,  of  Berlin. 
The  Tannins,  Vol.11.    By  Henry  Trimble,  Ph. M. 
A  Monograph  on  the  History,  Preparation,  Properties,  Methods  of  Estima- 
tion and  Uses  of  the  Vegetable  Astringents.  J.  B.  Iyippincott  Company,  Phila- 
delphia.   121110.    Pp.  172. 
The  first  volume,  which  appeared  in  December,  1891,  was  devoted  to  a  gen- 
eral history  of  the  tannins,  the  methods  of  extraction  and  estimation,  and 
especially  considered  gallo-tannic  acid.  The  second  volume,  now  before  us,  is 
especially  devoted  to  the  tannins  existing  in  the  barks  of  the  various  species 
of  oak,  the  mangrove,  the  canaigre  and  in  the  chestnut.  It  is  an  unusually 
interesting  and  carefully  prepared  monograph,  treating  the  subjects  in  an 
instructing  manner,  and  serves  well  as  an  illustration  of  the  numerous  fields  in 
which  chemists  should  specialize  their  study  and  investigations. 
The  first  section  of  the  volume  treats  of  the  sources  of  the  oak  tannins.  A 
very  commendable  feature  of  this  section  is  the  brief  descriptions  of  the  dis- 
tinguishing characters  and  well  executed  sketches  of  the  leaves  and  acorns  of 
our  oaks  of  the  Eastern  United  States,  the  barks  of  which  have  been  gener- 
ally examined  by  the  author.  The  suggestion  is  ventured  that  a  reference  to 
these  pages  would  enable  the  manufacturers  to  produce  definite  products  by 
keeping  separate  the  material  and  products  from  the  various  species  of  oaks. 
The  investigations  of  the  author  are  particularly  valuable,  and  accepted  as 
authority,  as  in  each  instance  the  work  was  performed  on  material,  the  source 
and  botanical  origin  of  which  was  known,  thus  removing  the  uncertainty  which 
attended  most  of  the  investigation  in  this  field  made  in  the  past. 
The  second  section  gives  the  history  of  the  oak  tannins,  and  the  various  inves- 
tigations from  1792  to  date  are  briefly  reviewed.  The  additions  to  the  knowl- 
edge of  this  group  are  chronicled,  and  the  source  of  some  of  the  errors  intro- 
duced in  their  work  is  pointed  out  and  attention  is  directed  to  the  discrepancies 
existing  in  the  reported  results.  This  concise  resume  of  the  literature  will  be 
exceedingly  useful  to  future  investigators  in  the  vegetable  astringents,  as  it 
places  in  a  compact  form  the  information  from  the  various  scattered  sources, 
many  of  which  were  not  accessible  to  the  average  student.  The  various  pro- 
cesses of  preparation  and  purification  of  these  tannins,  as  well  as  their  proper- 
ties 1  and  methods  of  estimation,  are  described,  accompanied  by  criticisms, 
suggestions  and  improvements,  as  results  of  the  original  investigations  of  the 
author.  These  materially  enhance  the  value  of  the  work.  Acetone  is  recom- 
mended as  a  solvent  in  the  extraction  in  place  of  ether.    The  pure  oak  tannins 
