Am.  Jour.  Pharm.  ) 
Sept.,  1877.  J 
Varieties. 
47i 
Bismuth. —  Ammonium  chloride  is  the  best  solution  from  which  to  obtain  an 
adherent  deposit.  The  solution  should  contain  25  to  30  grams  per  liter,  and  should 
•be  cold.  With  a  single  DanielTs  cell,  the  deposit  takes  place  slowly  and  to  a  small 
extent  j  with  a  Bunsen's  element  it  is  quickly  formed  and  very  adherent.  When 
polished,  it  has  a  shade  intermediate  between  those  of  antimony  and  oxidized  silver. 
It  is  not  altered  in  dry  air. 
Antimony  separates  well  from  its  double  chloride  with  ammonium,  at  ordinary 
temperatures.  The  deposit  is  black,  and  may  be  advantageously  used  to  replace 
platinum.  When  deposited  from  the  chloride  by  a  weak  current  on  a  fragment  of 
antimony,  the  metallic  layer  has  very  curious  explosive  properties. 
Palladium  may  be  deposited  from  a  perfectly  neutral  solution  of  palladium- 
ammonium  chloride. — Jour.  Chem.  Soc,  Feb.,  from  Compt  rend. 
New  Test  for  Acids  and  Alkalis. — F.  Frebault  uses  potassium  and  sodium 
>picramates,  which  have  a  bright  red  color,  and  turn  greenish-yellow  when  treated 
with  the  weakest  acids.  Filter-paper  soaked  in  a  solution  of  calcium  picramate  may 
be  used  for  the  same  purpose,  and  may  advantageously  replace  litmus. — Ibid.,  Mar., 
from  J.  Chim.  Pharm. 
Method  of  Testing  for  Impurities  in  Potassium  Iodide. — The  novelty  of  Lepage's 
•method  consists  in  dissolving  out  all  potassium|iodide  from  the  commercial  sample 
with  80  per  cent  alcohol,  and  testing  for  the  impurities, — carbonate,  iodate,  sulphate, 
chloride  and  bromide  of  potassium,- — in  the  residue,  by  the  ordinary  processes. — 
Ibid,  from  Ibid. 
Preparation  of  Iodic  Acid. — When  this  acid  is  prepared  by  passing  chlorine 
into  water  containing  suspended  iodine,  twenty  parts  of  water  to  1  of  iodine  must 
be  taken,  in  order  to  transform  all  the  iodine  into  acid  ;  otherwise  chloride  of  iodine 
is  formed. — G.  Sodini.    Ibid.,  from  Gaz.  Chem.  ital. 
Precipitated  Sulphur. — Instead  of  acting  on  polysulphide  of  calcium  with  pure 
hydrochloric  acid,  the  commercial  acid  free  from  arsenic  is  used  ;  the  precipitate 
collected  and  washed  is  again  mixed  with  acid,  and  left  for  about  an  hour,  shaking 
from  time  to  time;  the  grayish  color  then  disappears  suddenly}  the  acid  is  finally 
decanted,  and  used  for  a  second  operation. — M.  Sansoni  and  C.  Capellani.  Ibid., 
.from  Ibid. 
Gelatin  as  a  Reducing  Agent. — On  adding  an  excess  of  mercuricXchloride  to  a 
solution  of  gelatin  acidulated  with  hydrochloric  acid,  a  flocculent  precipitate  is  pro- 
duced, which  soon  agglutinates  and  sinks  to  the  bottom  of  the  vessel  as  a  dense 
■layer.    This  swells  up  in  pure  water  to  a  transparent  jelly,  which  subsequently  dis- 
