382 
EDITORIAL. 
Regnault.  who,  though  young  in  years,  is  experienced  in  the  paths  of  che- 
mical philosophy,  and  a  bright  star  among  the  savans  of  Paris.  The  original 
is  in  four  duodecimo  volumes.  In  its  American  dress  the  work  is  com- 
prised in  two  large  octavos.  The  letterpress  is  larger  and  more  comfort- 
able to  the  eyes  than  the  original  ;  the  numerous  excellent  illustrations  in  the 
latter  are  well  copied,  and  altogether  it  is  highly  creditable  to  the  publishers. 
The  translator  has  executed  his  part  thoroughly ;  no  gallicisms  or  obscure 
phrases  have  been  noticed.  The  Editors  appear  to  have  given  due  attention 
to  the  proof  sheets.  They  have  very  properly  introduced  Fahrenheit  numbers 
for  temperature,  and  the  hydrogen  scale  of  equivalents,  and  with  equal  pro- 
priety have  retained  the  decimal  weights  and  measures  of  the  original.  Be- 
sideg;  they  have  added  numerous  foot  notes,  either  explanatory  of  the  text  or 
in  relation  to  recent  observations.  Several  of  these  are  valuable  additions. 
Let  us  now  look  into  the  book  a  little  closer,  and  see  in  what  respect  M.  Reg- 
nault claims  merit  as  a  chemical  writer.  The  first  feature  that  strikes  one 
is  the  absence  of  the  chapters,  usually  preliminary  in  English  chemical  books, 
on  the  chemistry  of  the  imponderables.  The  introductory  chapter  of  78  pages, 
after  explaining  the  divisibility  of  matter,  aggregative  and  chemical  affinity, 
and  the  law  of  multiple  proportion  with  chemical  nomenclature  and  symbols, 
is  chiefly  devoted  to  a  very  lucid  account  of  crystallography,  copiously  il- 
lustrated with  wood  cuts,  in  which  the  several  systems  are  explained.  This 
chapter  will  prove  very  useful  to  the  student,  as  the  importance  of  crystalline 
form,  both  in  natural  and  chemical  bodies,  as  a  distinctive  characteristic,  is 
yearly  increasing. 
The  general  classification  of  the  elements  is  as  metalloids  and  metals.  The 
whole  work  exhibits  an  unusual  tendency  to  apply  chemical  facts  to  the  arts, 
and  in  the  description  of  processes  it  is  apparent  that  the  author  is  thoroughly 
conversant  with  what  he  describes,  distinguishing  which  are  the  best,  and 
why  :  again,  he  brings  in  many  facts  and  phenomena  just  in  the  place  they 
are  naturally  called  up  in  the  progress  of  the  work: — for  instance,  under 
water,  the  several  physical  facts  regarding  its  congelation,  vaporization,  con- 
densation and  solvent  power,  usually  spoken  of  under  caloric,  are  noticed. 
Whilst  the  principle  of  the  safely  tube  and  Woulf's  apparatus,  and  the  theory 
of  volumes,  are  brought  in  under  the  compounds  of  nitrogen.  The  best  modes 
of  determining  and  separating  many  substances  are  specially  stated,  and  a 
recapitulation  of  important  chapters,  as  these  of  the  compounds  of  oxygen 
with  nitrogen,  sulphur  and  phosphorus,  is  appended,  of  much  use  to  the 
student.  We  observe  that  arsenic  is  placed  among  the  non-metallic  bodies 
along  with  phosphorus;  and  oxalic  acid,  cyanogen  and  hydrocyanic  acid 
under  carbon. 
In  the  remarks  preliminary  to  the  metals,  a  considerable  space  is  devoted 
to  the  geological  structure  of  the  earth  and  of  metallic  veins,  illustrated  with 
cuts.  The  physical  properties  of  the  metals,  their  chemical  properties  and 
relations  to  oxygen  and  other  metalloids,  and  their  alloys,  are  there  noticed; 
and  finally,  a  most  interesting  chapter  on  the  general  characters  and  forma- 
tion of  salts.    M.  Regnault  gives  as  the  definition  of  a  salt,  "  every  combi- 
