^sep™',  1872.* }    Action  of  Phosphoric  Acid  on  Morphia .  417 
INK  IN  CAKES 
May  be  prepared  by  evaporating  good  ink  to  dryness  in  shallow 
dishes,  but  the  best  results  are  obtained  by  dissolving  Chinese  ink  in 
-water. 
MARKING-INK. 
This  substance  is  so  well  known,  that  little  may  be  said  on  the  sub- 
ject. The  process  is  founded  on  the  chemical  fact,  that  by  applying 
heat  to  a  salt  of  silver  in  combination  with  other  ingredients,  the  writ- 
ing becomes  immediately,  and  should  remain  permanently,  black ;  the 
formula  of  Professor  Redwood  is  a  good  one : 
Dissolve  separately — nitrate  of  silver  one  ounce,  crystal  carbonate 
of  soda  one  and  a  half  ounce ;  mix  the  solutions,  and  collect  the  pre- 
cipitate on  a  filter ;  wash  well,  then  introduce  the  moist  precipitate 
into  a  mortar,  and  add  eight  scruples  of  tartaric  acid :  triturate  till 
effervescence  ceases  ;  then  add  of  liq.  ammonise  fort,  a  sufficient  quan- 
tity to  dissolve  the  tartrate  of  silver,  to  which  add  four  fluid-drachms 
of  archil,  four  drachms  of  powdered  white  sugar,  and  twelve  drachms 
of  powdered  gum  arabic,  and  make  up  to  six  fluidounces.  if  required, 
with  distilled  water. 
CRIMSON  MARKING-INK 
Is  prepared  by  adding  six  grains  of  carmine  to  the  liquor  ammonite  of 
the  above  formula,  but  it  soon  loses  its  crimson  color,  and  becomes, 
like  other  marking-inks,  a  black  color. 
In  conclusion,  I  cannot  lay  aside  this  subject  without  referring  to 
the  beauty,  brilliancy  and  variety  of  color  produced  from  aniline, 
whereby  we  can  procure  any  shade  from  the  most  brilliant  scarlet  to 
the  most  sombre  black,  and  should  we  at  any  time  be  deprived  of  ink 
from  the  present  sources,  we  may  rest  content  that  so  long  as  our  coal 
fields  yield  their  sparkling  riches,  so  long  may  we,  without  fear,  look 
forward  to  an  unlimited  supply  of  "  Our  Writing  Fluids/' — Chemist 
and  Druggist,  Lond.,  June  15,  1872. 
ACTION  OF  PHOSPHORIC  ACID  ON  MORPHIA. 
In  a  paper  read  before  the  Chemical  Society,  June  6th,  the  author 
observes  that  the  action  of  phosphoric  acid  upon  morphia  is  some- 
what similar  to  that  on  codeina,  the  polymerides  being,  however,  at 
the  same  time,  converted  into  "  apo  "  derivatives  by  the  removal  of 
water.    The  mixed  apo  bases  are  immediately  precipitated  by  sodium 
27 
