Am.  Jour.  Pbarm.  \ 
January,  1898.  j 
Reviews. 
5i 
Much  practical  information  is  contained  in  the  144  pages,  and  the  whole  is 
made  more  attractive  and  available  by  the  26  illustrations. 
Practical  Exercises  in  Electrochemistry.  By  Dr.  Felix  Oettel. 
Translated  by  Edgar  F.  Smith.   P.  Blakiston,  Son  &  Co.,  Philadelphia.  1897. 
Much  is  heard  in  these  days  about  the  study  of  electrochemistry,  but  the 
student  is  at  a  loss  to  know  where  to  make  a  beginning.  This  book  of  92 
pages  supplies  one  with  the  necessary  technique  of  the  subject.  By  working 
through  this  book  the  student  would  have  his  ideas  enlarged  similarly  to  one 
who  has  taken  a  practical  course  in  chemistry.  Many  of  the  experiments  are 
types  of  definite  processes,  which  are  not  only  instructive,  but  suggestive. 
Much  credit  is  due  Dr.  Smith  for  rendering  this  and  the  foregoing  work  avail- 
able to  English-speaking  students. 
Recueie  des  eois  de  ea  Bioeogie  Generate.  Par  A.  L.  Herrera,  Ancien 
President  de  la  Soci^te  Alzate.  Laureat  de  l'lnstitut  Smithsonien.  Mexico. 
1897. 
This  is  a  compilation  of  what  may  be  termed  laws  in  the  science  of  biology, 
which  are  so  well  established  as  to  be  used  as  the  basis  for  theories,  of  which 
there  are  a  number  in  existence.  The  great  laws  are  those  concerning  time, 
unity,  elementary  life,  particular  ends,  differentiation,  variability,  adaptation, 
selection,  distribution,  struggle  for  existence  and  evolution.  These  are  subdi- 
vided, and  the  law  governing  each  subdivision  is  briefly  stated  in  a  way  to 
make  the  whole  a  valuable  reference  book  for  biologists.  It  is  evidently  the 
result  of  much  investigation  by  the  author,  as  well  as  a  close  study  of  the 
results  of  others. 
Observations  on  Recent  Cases  of  Mushroom  Poisoning  in  the  Dis- 
trict of  Columbia.  By  Frederick  V.  Coville.  Department  of  Agriculture, 
Division  of  Botany.    Circular  No.  13. 
With  the  aid  of  photographic  reproductions  and  a  clear  description,  the 
author  is  able  to  give  much  information  that  will  assist  in  distinguishing  the 
edible  from  the  poisonous  mushrooms.  Very  sensible  advice  is  given  to  the 
novice,  who  is  too  apt  to  rely  on  printed  descriptions,  namely,  to  get  his 
authority  for  the  identity  and  qualities  of  each  one  he  adds  to  his  list  from  some 
person  having  unquestioned  expert  knowledge  of  the  subject. 
North  American  Lemnace^E.  By  Charles  Henry  Thompson.  Printed  in 
advance,  from  the  Ninth  Annual  Report  of  the  Missouri  Botanical  Garden. 
The  natural  order  I/emnaceae  has  been  especially  studied  by  such  authorities 
as  Schleiden,  Austin,  Hegelmaier,  Engelmann  and  Torrey.  The  author  has 
sought  to  bring  together  the  results  of  these  investigations,  and  include  his  own 
researches  of  the  past  two  years.  The  outcome  is  a  valuable  revision  of  the 
American  species  in  this  order. 
The  Phyeogeny  and  Taxonomy  of  Angios perms.  By  Charles  E.  Bessey, 
Ph.D.  Address  of  the  retiring  president,  delivered  before  the  Botanical 
Society  of  America,  at  its  third  annual  meeting,  Toronto,  Ontario,  August  17, 
1897. 
With  the  aid  of  diagrams  this  rather  technical  subject  has  been  made  clear 
and  popular  in  character. 
