VARIETIES. 
377 
and  consequently,  if  the  air  is  heated  to  redness,  which  conveys  these  germs, 
the  above  phenomena  cannot  take  place.  The  authors  have  filtered  air 
through  cotton  'wool,  which  air  they  have  tested  by  allowing  it  to  pass  over 
substances  which  readily  ferment  or  putrefy,  and  have  arrived  at  the  fol- 
lowing conclusions : — 1.  That  the  filtered  air  will  not  putrefy  flesh  recently 
boiled  with  water.  2.  That  broth  will  remain  many  weeks  unchanged  in 
this  air.  3.  That  the  sweet  wort  from  malt  will  remain  unaltered  for  a 
week,  and  not  undergo  fermentation.  On  the  contrary,  the  coagulation  of 
milk  goes  on  as  rapidly  in  filtered  air  as  in  that  which  is  not  filtered. 
Flesh,  which  probably  was  not  sufficiently  heated  before  the  experiment, 
putrefied  in  filtered  air.  The  authors  would  draw  also  from  their  experi- 
ments the  conclusions  that  there  is  a  spontaneous  decomposition,  for  which 
oxygen  only  is  necessary,  and  which  causes  the  putrefaction  of  flesh  with- 
out water,  and  that  of  the  caseine  of  milk,  which  converts  the  sugar  of 
milk  into  lactic  acid,  but  that  the  fermentation  of  malt  wort,  &c,  does  not 
belong  to  this  category,  as  to  effect  this  result  some  organic  admixture  of 
the  air  is  necessary,  which  can  be  removed  by  a  Alteration  or  a  red  heat. 
— Ann.  of  Pharm.  from  Annalen  der  Chemie. 
On  forming  vessels  of  gold  by  the  aid  of  phosphorus. — The  property  of 
phosphorus,  of  precipitating  certain  metals  from  their  solution  has  long  been 
known  ;  and  gold  is  among  the  number.  M.  Levol  has  used  this  process 
in  forming  gold  vessels  useful  in  chemical  research.  He  takes  the  per- 
chlorid  of  gold,  and  places  in  it,  at  the  ordinary  temperature,  some  phos- 
phorus, moulded  of  a  form  convenient  to  serve  as  a  nucleus  for  the  vessel 
of  gold.  To  give  the  phosphorus  the  desired  shape,  it  is  melted  in  a  water- 
bath  near  GO^C.  in  temperature,  within  a  vessel  of  glass  having  the  form 
required.  After  cooling  it,  the  phosphorus  is  taken  out  solid,  from  its  en- 
velop, breaking  it,  if  it  be  necessary.  The  precipitation  of  the  gold  or  the 
construction  of  the  vessel  is  then  begun  ;  and  it  finally  remains  only  to 
remove  the  phosphorus  by  re-melting  it  and  washing  by  the  aid  of  boiling 
nitric  acid  until  the  last  traces  are  removed. — Sittiman's  Journal. 
Gilding  of  Silk,  &c. — Commerce  has  furnished  for  some  time  a  kind  of 
silk  treated  by  a  galvanoplastic  method  ;  the  threads  produce  a  costly 
fabric  of  wonderful  solidity.  The  author  of  the  process  is  M.  Pouilly. 
He  first  metallises  the  silk,  then  covers  it  with  a  thin  layer  of  copper  and 
finally  applies  the  gold  by  the  aid  of  the  galvanic  battery. — Ibid. 
