io8 
Reviews. 
j  A.m.  Jour.  Pbarm. 
I        Feb.,  189». 
but  few  omissions  of  unimportant  matters  having  no  reference  to  chemistry, 
the  signs  being  replaced  by  the  Latin  chemical  terms  used  by  Scheele.  As  an 
introduction  to  each  document  its  contents  are  briefly  indicated,  and  the  text 
is  in  nearly  each  case  followed  by  brief  explanatory  notes,  frequently  of  a  his- 
torical character.  The  letters  are  preceded  by  a  biography  of  Scheele,  occupy- 
ing 28  printed  pages,  and  by  a  list  of  the  titles  of  his  published  essays. 
It  is  impossible  to  enter  in  this  place  into  details  ;  but  it  may  be  stated  that 
the  documentary  evidence  here  pioduced  shows  not  only  the  wide  extent  of  his 
experimental  researches,  but  likewise  his  clear  views  and  deductions  ;  and  it 
appears  that  he  is  doubtless  entitled  to  the  honor  of  being  the  first  discoverer 
of  chemical  bodies,  other  than  those  that  have  heretofore  been  credited  to  him. 
Thus  it  is  shown,  that  during  the  years  1771  and  1772  Scheele  had  isolated 
oxygen,  which  he  at  first  called  :'aer  vitriolicus,"  from  mercuric .  carbonate, 
mercuric  oxide,  silver  carbonate,  magnesium  nitrate  and  from  a  mixture  of 
black  manganese  and  arsenic  acid.  These  researches,  which  included  also  the 
chief  properties  of  the  gas,  preceded  Priestley's  discovery  (August  1,  1774), 
from  two  to  three  years  ;  but  they  do  not  in  the  least  detract  from  the  honor  due 
to  Priestley  for  his  independent  discover)-,  nor  do  they  lessen  the  immense 
value  of  Lavoisier's  researches,  upon  which  the  structure  of  modern  chemical 
science  has  been  erected. 
The  work  has  been  published  both  in  the  Swedish  and  German  languages, 
the  latter  version  having  been  prepared  by  Paul  Berndt  and  revised  by  Prof. 
E.  von  Meyer. 
Traite  general  (V Analyse  des  Beurres,  preparation,  caracteres,  composition, 
alterations  et  falsifications  ;  methode  geuerale  d'analyse,  discussion  et  appre- 
ciation des  resultats.  Par  A.  J.  Zuue,  redacteur  en  chef  du  Moniteur  du  Prati- 
cien.  Chez  l'auteur,  108  bis,  rue  de  Renues.  Paris  ;  et  chez  l'imprimeur- 
editeur,  A.  Allard,  Braine-l'Alleud,  Belgique.  Complet  en  deux  volumes  : 
prix,  25  francs. 
A  general  treatise  on  the  analysis  of  butters.  Vol.  I.  Pp.  490,  with  83  illus- 
trations aud  63  tables  inserted  in  the  text.  Vol.  II.  Pp.  340,  wTith  270  illustra- 
tions and  85  tables  inserted  in  the  text,  and  with  r4  plates. 
These  two  volumes  constitute  a  very  comprehensive  and  meritorious  mono- 
graph on  butter,  its  substitutes  and  adulterations,  and  their  recognition  and 
determination.  The  first  volume  is  devoted  to  general  considerations  wmich 
are  discussed  in  ten  chapters,  beginning  with  the  preparation  and  conservation 
of  butter  and  of  the  numerous  artificial  compounds  used  in  place  of  the  natural 
product.  In  the  next  four  chapters  the  characteristics  of  these  articles  are 
considered,  as  organoleptic  characters  (appearance,  consistence,  color,  odor 
and  taste);  physical  characters  (fusing  and  solidifying  points,  density,  solu- 
bility, etc.);  optical  characters  (crystallization,  polarization,  etc.),  and  behavior 
with  various  reagents,  such  as  sulphuric  acid,  nitric  acid,  silver  nitrate,  gold 
chloride,  etc.  The  two  following  chapters  treat  of  the  proximate  composition 
as  determined  by  different  authors,  viz  :  fat,  water,  casein,  salt,  palmitin,  oleiu, 
butyrin,  etc. ;  and  the  subsequent  chapter  gives  an  account  of  the  products — 
the  various  acids  and  glycerin — obtained  by  saponification  ;  while  the  con- 
cluding chapters  discuss  the  processes  recommended  by  various  others  for  the 
detection  of  falsifications,  and  the  alterations  which  occur  in  butter  and  other 
