474 
Varieties. 
f  Am.  Jour.  Pharm, 
t     Oct.  1,  1873. 
its  contents  are  immersed  in  cold  water  for  some  twelve  hours  or  so,  it  is  found 
to  undergo  a  chemical  molecular  change,  and  to  become  solid  and  insoluble. 
The  egg,  and  fluid  in  which  it  is  immersed,  is  now  heated  to  boiling,  when  the 
fibrin  will  be  found  ready  for  use. — Journ.  Applied  Ckem.,  July,  1873. 
\  Anti- Neuralgic  Snuff. — The  Rivista  Clinica  di  Bologna  mentions  an  anti- 
neuralgic  snuff  prescribed  with  success  in  cases  of  facial  neuralgia,  by  Dr. 
Scriffignano.  The  base  of  the  snuff  is  quinine,  and  its  composition  as  fol- 
lows :  Citrate  of  quinine,  ten  grains  ;  very  strong  exciting  snuff  (tobacco), 
fifteen  grains.  The  medicament  is  said  to  act  almost  directly  on  the  diseased 
nerve  through  the  ethmoidal  thread  of  the  nasal  ramus  of  Willis's  ophthalmic, 
a  branch  of  the  fifth  pair. — Philada.  Med.  Times,  Aug.  9,  1873,  from  London 
Lancet. 
Gilding  Iron. — Soduira  amalgam  is  said  to  be  advantageous  as  a  means  of 
simplifying  the  method  of  dry  gilding  iron,  and  for  painting  gold  designs  thereon. 
By  simply  rubbing  with  the  amalgam,  the  surfaces  of  iron  and  similar  metals, 
although  oxidized,  are  at  once  amalgamated.  Some  solution  of  chloride  of 
gold  is  then  applied  quickly  on  the  amalgamated  surface,  and  the  mercury 
volatilized  by  the  heat  of  a  lamp  or  fire.  A  very  uniform  gilding  is  thus  ob- 
tained, admitting  of  high  polish.  With  silver  and  platinum  salts  similar  results 
are  obtained.— ./ow  Franklin  Institute,  Sept.,  1873. 
Determination  of  Chloral.— V.  Meyer  and  H.  HafFter. — The  authors  remark 
that  chloral  hydrate  is  often  found  very  impure,  whence  a  simple  and  accurate 
method  for  its  quantitative  examination  becomes  needful.  With  aqueous  solu- 
tions of  alkalies  chloral  hydrate  is  completely  resolved  into  chloroform  and 
alkaline  forruiate  according  to  the  equation,  O2  CI3  H3  O2  +  Na  0  H  =  C  H 
(JI3  +  H  C  O2  Na-f  Ho  O.  1  equivalent  of  chloral  hydrate  neutralizes  1 
equivalent  of  soda,  or  165  5  grms.  of  the  former  require  1000  c.c.  of  normal 
solution  of  soda.  If,  therefore,  a  weighed  amount  of  the  sample  under  exami- 
nation is  mixed  with  a  known  excess  of  normal  soda  solution,  and  the  remain- 
ing excess  of  soda  is  determined  by  titration  with  standard  acid,  the  soda  con-* 
sumed  and  the  corresponding  amount  of  pure  chloral  hydrate  are  found  by  the 
equation — 
(a— b)  165-5 
x  =  K  '   grm. 
1000  8 
tt  denoting  the  number  of  c.c.  of  normal  soda  consumed,  and  b  the  c.c.  of  nor- 
mal acid  used  for  titration.  If  free  hydrochloric  acid  is  present  as  an  impurity, 
it  is  neutralised  by  shaking  up  the  aqueous  solution  with  pure  carbonate  of 
lime,  and  expelling  the  free  carbonic  acid  by  prolonged  agitation  in  the  meas- 
uring cylinder. —  Chem.  News  (Lond.).  June  27,  1873. 
On  Crystalline  Protiodidt  of  Mercury. — P.  Yvon. — This  compound  is  best 
obtained  by  heating  mercury  and  iodine  in  equivalent  proportions,  in  sealed 
flasks,  upon  the  sand  bath.  The  temperature  must  not  be  allowed  to  exceed 
250°.    The  upper  portion  of  the  flask  will  be  found  lined  with  crystals  of  a  fine 
