Am.  Jour.  Pharm. 
Jan.,  1886. 
Casein  in  Milk. 
43 
yet  it  is  immediately  precipitated  in  the  serum  from  rennet,  and  as 
this  serum  has  an  acid  reaction,  it  follows  that  an  albuminate  has 
been  formed  which  holds  the  calcium  phosphate  in  solution  as  an  acid 
albuminate.  Soxhlet  considers  that  the  separation  of  casein  is  accom- 
panied by  the  formation  of  lactic  acid  ;  the  author  has  been  unable 
to  detect  this  acid  in  the  whey,  but  he  has  found  several  albuminoids, 
and  prefers  to  consider  the  formation  of  acid  albuminate  by  hydration 
as  most  probable. 
If  milk  contains  lactic  acid  (1  per  1000),  the  action  of  the  rennet 
is  more  rapid,  but  the  casein  produced  contains  a  smaller  percentage 
of  ash  than  it  should  normally,  and  is  of  a  bitter  taste ;  if  the  quan- 
tity of  acid  is  more  than  1 J  per  1000,  then  the  cheese  is  uneatable. 
In  a  cheese  prepared  under  normal  conditions,  there  is  present  8*25— 
8'75  calcium  compounds,  which  are  present  in  the  proportion  of  1 
mol.  tricalcium  to  1  mol.  monohydrocalcium  phosphate.  Sometimes 
part  of  the  calcium  is  replaced  by  magnesium. — Jour.  Chem.  Soc, 
1885,  p.  1083;  Land.  Vers.-Stat,  1885,  p.  392. 
Ptomaines. — By  F.  Coppola  {Gazzetta,  xiv,  571-572  )— In  a 
former  memoir  on  the  ptomaines  the  author  has  pointed  out  the 
probability  that  their  genesis  is  due  to  the  processes,  such  as  Dragen- 
dorff's,  used  for  their  extraction;  a  description  is  given  of  experi- 
ments on  the  putrefaction  of  large  quantities  of  various  tissues  and 
organs,  such  as  muscle,  pancreas,  spleen,  brain  of  dog,  etc.,  kept 
from  free  access  of  air,  and  at  the  ordinary  temperature.  For  a 
fortnight  the  putrefying  mass  had  an  acid,  but  at  the  end  of  six 
weeks  a  decidedly  alkaline  reaction.  Both  the  liquid  and  the1  solid 
portions  of  the  resultant  mass  were  extracted  with  benzene.  The 
extract,  on  evaporation,  gave  an  abundant  yellow  residue,  which 
showed  all  the  characteristic  reactions  of  alkaloids.  From  this  result 
it  is  inferred  that  the  process  of  putrefaction  is  not  capable  of  pro- 
ducing ptomaines,  but  that  the  acid  reaction  conduces  to  the  de- 
composition of  lecithins  with  generation  of  a  substance  having  the 
properties  of  an  alkaloid. 
The  relatively  small  quantity  obtained  from  more  than  2  kilos,  of 
putrefying  material  seems  further  to  indicate  that  the  alkaloids 
extracted  by  the  Dragendorff.  and  Stas-Otto  methods  are  mainly 
formed  by  the  processes  employed  for  their  extraction. — Jour.  Chem, 
Soc.,  1885,  p.  913. 
