^"^silTis^s^'""'}  Reviews  and  Bibliographical  Notices.  43 1 
Holzstichen,  Heidelberg:  Winter's  Universitats-Buchhandlung,  1874.  8vo, 
pp.  166.    Price,  I  5-6  thaler. 
The  Chemistry  of  Fermentation,  in  Eleven  Lectures.    With  23  Wood-cuts. 
The  author  has  intended  this  work  as  a  continuation  of  his  larger  work  on  agri- 
cultural chemistry,  published  a  few  years  ago,  and  as  an  introduction  into  the  tech- 
nology of  such  trades  in  which  fermentation  is  employed.  Fermentation  processes 
have  been  known  since  the  remotest  periods  in  history ;  but  the  definition  of  the 
term,  as  at  present  employed  in  science,  has  not  been  definitely  settled.  The  class 
of  fermentation  processes,  however,  which  are  of  importance  in  agricultural  pur- 
suits, may  be  defined  as  comprising  those  chemical  alterations  of  dissolved  organic 
compounds  which  occur  under  the  influence  of  low  organisms  (fungi,  bacteria)  des- 
titute of  chlorophyll.  In  these  cases  fermentation  is  induced  by  what  is  termed 
organized  ferments^  while  substances  which  induce  chemical  changes  without  the  aid 
•of  organisms  may  be  called  chemical  ferments.  The  author  confines  himself  to  the 
former  class,  and  considers  more  especially  alcoholic  fermentation,  which  has  been 
most  frequently  the  subject  of  critical  investigations.  He  reviews  in  a  very  engag- 
ing manner  the  older  views  concerning  fermentation  and  allied  processes,  and  enters 
more  fully  into  the  consideration  of  the  various  theories  entertained  since  the  time 
of  Lavoisier,  and  into  the  gradual  development  of  the  views  of  Liebig  and  Pasteur, 
and  the  observations  of  other  chemists.  The  adoption  of  Pasteur's  views,  that  the 
production  of  alcohol  from  sugar  is  the  result  of  the  vegetation  of  low  fungi,  brings 
the  author  to  the  questions  of  spontaneous  generation  and  the  nature  and  life  of 
•low  organisms,  including  their  chemical  constitution  and  development,  all  being 
critically  and  entertainingly  considered.  The  last  chapter  is  devoted  to  acetic  fer- 
mentation, and  briefly  alludes  also  to  certain  changes  occurring  in  wine,  the  pro- 
duction of  lactic  and  butyric  acids,  and  to  other  chemical  decompositions  which  are 
asserted  or  believed  to  be  due  to  fermentation. 
We  know  of  no  other  work  which  treats  as  fully  and  impartially  of  fermentation, 
nowhere  hiding  defects  of  investigations,  or  omitting  to  point  out  results,  even 
though  they  might  serve  or  be  used  as  arguments  in  favor  of  theories  opposite  to 
the  views  of  the  author.  It  needs  scarcely  be  stated  here  that  the  latest  investiga- 
tions have  found  a  place  in  this  work,  which  is  so  thorough  and  instructive,  and  at 
the  same  time  so  entertaining,  that  no  reader  will  peruse  it  without  satisfaction. 
Anleitung  xur  Analyse  der  Aschen  und  Minerah-wasser.  Von  Robert  Bunsen.  Mit 
einer  lithographirten  Tafel  und  sechs  Tabellen.  Heidelberg :  Carl  Winter's 
Universitats-Buchhandlung.    1874.    ^^o,  pp.  64. 
A  Guide  for  the  Analysis  of  Ashes  and  Mineral  Waters.  With  one  lithographic 
plate  and  six  tables. 
A  work  on  analysis  from  the  author's  pen  needs  scarcely  any  words  of  commen- 
dation. The  one  before  us  is  a  reprint  from  the  "Annalen  der  Oenologie,"  and 
from  the  "  Zeitschrift  fiir  analytische  Chemie."  The  first  part  treats  of  the  analysis 
of  ashes,  under  three  headings :  preliminary  manipulation,  analysis  of  the  portion 
soluble  in  water  and  analysis  of  the  portion  insoluble  in  water.  The  second  part, 
the  analysis  of  mineral  waters,  describes:  ist,  work  at  the  mineral  spring  j  zd, 
analysis  of  the  water,  and  3d,  calculation  of  the  results.  The  work  is  intended  for 
those  who  are  already  acquainted  with  chemical  analysis  and  accustomed  to  exact- 
