328  Notices  respecting  New  Books. 
direct  than  that  indicated  above.  The  evaporation,  if  suffi- 
ciently rapid,  may  maintain  a  permanent  difference  in  con- 
centration between  the  body  of  the  liquid  and  the  portions 
near  the  surface,  in  spite  of  the  tendency  for  diffusion,  thus 
giving  the  equivalent,  from  the  point  of  view  of  surface 
separation,  of  a  stronger  solution.  This  effect  will  only 
operate  to  any  large  extent  when  increase  of  concentration 
greatly  increases  the  power  of  forming  an  elastic  surface, 
i.  e.  in  the  case  of  very  dilute  solutions. 
The  University,  Leeds, 
Sept.  5,  1905. 
XXVI.  Notices  respecting  New  Books. 
Lehrbuch  der  PhysiJc.  Yon  0.  D.  Chwolsojst,  Prof.  Ord.  an  cler 
Kaiserl.  TJniversitat  zu  St.  Petersburg.  Dritter  Band :  Die 
Lehre  von  cler  Warme.  Uebersetzt  von  E.  Berg.  Mit  259 
eingedruckten  Abbildungen.  Braunschweig :  F.  Yieweg  und 
Sobn.     1905.     Pp.  xi  +  988. 
THE  translation  of  this  excellent  and  thoroughly  up-to-date  text- 
book is  neariug  completion,  and  Vol.  III.  is  now  before  us. 
It  is  divided  into  fourteen  chapters.  After  a  general  introduction, 
in  Chap.  I.,  on  heat  considered  as  a  form  of  energy  and  its  relation 
to  other  forms,  the  author  deals,  in  Chap.  II.,  with  thermometry, 
including  modern  methods  of  measuring  very  high  and  very  low 
temperatures.  The  next  four  chapters  are  devoted  to  the  deter- 
mination of  expansion  coefficients,  specific  heats,  thermo-chemistry, 
the  laws  of  cooling,  and  thermal  conductivity.  So  far  the 
treatment  follows,  more  or  less,  the  usual  arrangement  adopted 
in  standard  treatises  on  the  subject.  The  greatest  amount  of 
originality  is  displayed  in  the  remaining  portions  of  the  book, 
which  form  more  than  one-half  of  the  entire  volume.  Here  the 
author  deals  (in  Chapter  VIII.)  with  the  principles  of  thermo- 
dynamics (and  a  more  masterly  exposition  of  the  subject  could 
not  be  wished  for),  with  the  applications  of  thermodynamics  to 
various  phenomena  studied  in  the  earlier  chapters,  aud  to  changes 
of  physical  state  (Chaps.  IX.  to  XI.).  In  Chapter  XII.  we  have  an 
account  of  the  properties  of  saturated  vapours  and  hygrometry. 
Chapter  XIII.  deals  with  unsaturated  vapours,  the  critical  state, 
and  the  theory  of  corresponding  states.  The  concluding 
Chapter  XIV.  is  devoted  to  the  Phase  Rule  and  the  theory  of 
solutions. 
Little  need  be  added  to  the  praise  already  bestowed  upon  this 
comprehensive  and  remarkably  lucid  treatise.  To  the  advanced 
student  of  physics  it  is  a  veritable  treasure,  and  its  detailed  and 
careful  explanations,  with  its  wealth  of  excellent  illustrations, 
particularly  fit  it  for  purposes  of  private,  study;  while  its  numerous 
and  systematically  arranged  -bibliographical  references  render  it  a 
most  valuable  work  of  reference  to  all  interested  in  physics. 
