518 
Varieties. 
(  Am.  Jour.  Pharm^ 
t     Nov.  1, 1872. 
Carmine  Lakes. — These  very  beautiful  pigments  are  prepared  from  a  decoc- 
tion of  cochineal,  and  not  from  carminic  acid,  the  animal  matter  which  the 
insect  contains,  appearing  to  be  necessary  to  their  production.  The  mode  of 
preparing  the  finest  qualities  is  kept  a  secret  by  the  manufacturers  ;  but  I  will 
describe  two  processes  which  give  very  satisfactory  results.  The  first  consists- 
in  boiling  one  pound  of  ground  cochineal  with  two  gallons  of  water,  to  which 
has  been  added  one  ounce  of  alum.  It  is  then  boiled  for  three  minutes,  the 
liquor  is  allowed  to  settle,  and,  after  having  been  kept  for  several  days,  about 
one  ounce  of  a  bright  carmine  lake  is  produced.  For  the  alum  employed  in. 
this  process  cream  of  tartar  can  be  substituted.  The  second  process  consists 
in  boiling  for  three  hours  two  pounds  of  powdered  cochineal  in  thirty  gallons  of" 
water.  To  this  is  added  three  ounces  of  pure  saltpetre.  The  liquor  is  then 
boiled  again  and  left  to  settle.  The  clear  liquor  is  run  off,  and  after  two  or 
three  weeks  yields  a  fine  carmine  lake.  As  these  lakes  are  expensive,  they  are- 
often  adulterated  with  starch,  kaolin,  vermillion,  etc.  The  complete  solubility 
of  pure  carmine  lakes  in  ammonia  afford  a  ready  means  of  detecting  these  adul- 
terations.—  Grace  Calvert,  from  the  Am.  Gas  Light  Journ.  and  Chem.  Repertory*. 
Sept.  2,  1872. 
Orris  Root. — At  the  Pharmaceutical  Conference  at  Brighton,  Mr.  Henry 
Groves  read  a  paper  on  orris  root.  A  small  district  round  the  city  of  Florence 
seems  to  be  at  present  the  chief,  if  not  the  only,  source  of  orris  root.  The 
plants  yielding  it  are  Iris  florentina,  1.  germanica  and  /.  pallida,  and  the 
scraped  rhizome  is  the  portion  of  the  plant  which  occurs  in  the  market  as  orris 
root.  Large  quantities  of  these  roots  are  used  by  perfumers,  for  the  purpose 
of  blending  with  other  essences,  and  it  is  also  largely  used  for  tooth  powders* 
tind  for  the  composition  of  what  is  commonly  known  as  violet  powder.  A 
discussion  arose  as  to  whether  orris  root  contains  any  essential  oil.  Mr.  Has- 
elden  stated  that  he  had  frequently  endeavored  to  obtain  this  oil,  by  distilla- 
tion, but  had  failed  to  do  so.  Mr.  Umney,  London,  stated  that  he  had  dis- 
tilled many  tons  of  the  root,  and  had  obtained  the  essential  oil  in  the  form  of 
a  fatty  substance,  similar  to  cacao  butter.  This  substance  was  yielded  in  very 
small  quantity,  and  was  even  more  costly  than  otto  of  roses  ;  it  possessed  all 
the  fine  aroma  of  the  original  root. — Joum.  Applied  Science,  Sept.  1,  1872." 
New  Uses  of  Cellulose. — Chemists  have  long  known  that  cellulose  resists  the- 
action  of  the  most  powerful  reagents;  boiling  it  with  potash,  soda,  soap,  chlor- 
ide of  lime,  etc.,  has  no  effect.  Chloride  of  aluminum  attacks  it  somewhat;  the 
best  solvent  has  recently  been  discovered  by  Schweitzer,  which  consists  of  an 
ammoniacal  solution  of  the  oxide  of  copper  or  cupro-ammonium,  which  has  the 
property  of  completely  dissolving  cellulose  without  in  the  least  destroying  its 
chemical  or  physical  properties,  as  it  can  be  precipitated  in  a  perfectly  pure 
state  from  the  solution.  It  is  proposed  to  make  practical  use  of  this  important 
discovery  by  acting  upon  woody  fiber,  vegetable  tissue,  paper  stock,  rags  and 
refuse  sea-weed,  in  a  way  to  prepare  a  numerous  class  of  objects  from  them* 
The  solution  of  woody  fiber  is  accomplished  with  more  or  less  rapidity,  accord- 
ing to  the  condition  of  the  material ;  old  linen  and  cotton  rags  dissolve  imme- 
