Am.  Jour.  Pharm. ) 
Sept ,  1876.  J 
Varieties. 
429 
oil  of  vitriol  a  sulpho-acid  (a  crude  anthraquinone  product  practically  workable), 
which,  according  to  its  subsequent  purification  or  treatment,  furnishes  a  material — 
sulphanthraquinonic  acid — for  the  production  of  alizarin,  dyeing  with  scarlet  or 
blueish  tints. 
If  the  sodium  salt  of  sulphanthraquinonic  acid,  together  with  caustic  soda,  is 
heated  up  to  a  high  temperature,  the  alizarate  of  sodium,  CuH6Na204,  is  formed  as 
a  crude  fused  mass,  fit  for  farther  factory  purposes.  On  decomposing  this  salt  by 
an  acid,  the  alizarin  CuH804  is  obtained,  which,  carefully  purified,  comes  into  the 
trade  as  a  paste  of  10,  11,  15  or  20  per  cent,  concentration. 
The  preparation  and  use  in  this  watery  state  has  hitherto  proved  to  be  the  most 
advantageous  and  practical  form  of  alizarin,  as,  if  it  is  furnished  in  a  dry  state,  a 
perfectly  equal  solution  and  distribution  afterwards  in  the  dyeing  bath  or  in  the 
thickening  for  printing,  would  be  found  very  difficult. 
In  this  respect,  also,  is  shown  the  essential  difference  of  character  between  the 
alizarin  colors  and  the  anilin  colors,  which  latter  in  dyeing  form  only  a  precipitate 
on  the  fibre,  and  are  therefore  not  fast,  especially  when  exposed  to  the  influence  of 
the  light,  whereas  alizarin  is  a  fast  color,  because  it  is  an  acid  which,  in  combination 
with  other  mordants,  by  a  process  of  oxidation  similar  as  is  the  case  with  indigo, 
develops  the  red,  violet,  orange,  black  or  brown  tints  in  the  fibre,  thereby  producing 
it  fast  against  light  and  even  the  strongest  fulling. 
Alizarin  crystallizes  and  sublimes  in  red  needles.  By  a  double  decomposition  of 
a  solution  of  alizarate  of  potassium,  or  alizarate  of  sodium  and  soluble  metallic  salts, 
the  corresponding  difficulty,  soluble  alizarates,  are  obtained. 
The  most  interesting,  wonderful  fact  which  will  strike  our  minds  with  surprise 
while  investigating  the  above  processes,  is  that  in  coal  all  that  remains  from  the 
trees  and  vegetation  of  gigantic  antediluvian  forests  should  have  been  discovered  a 
raw  material,  and  from  it  a  color  of  exactly  the  same  chemical  identity  and  com- 
position as  that  which  so  far  was  extracted  only  from  the  root  of  the  insignificant 
plant  Rubia  tinctorum,  generally  known  as  madder.  After  such  success,  it  is  quite 
natural  that  efforts  have  been  made  to  go  still  a  step  farther  in  this  direction,  and 
that  we,  as  well  as  many  others,  hammer  already  for  a  considerable  time  at  the 
solution  of  another  immense  problem,  viz.,  the  articifial  production  of  real  indigo. 
VARIETIES. 
The  Antiseptic  Actions  of  Salicylic  and  Benzoic  Acids  on  Beer-worts 
and  Urine.  By  E.  von  Meyer  and  H.  Kolbe. — A  reply  to  certain  statements  of 
Fleck  in  opposition  to  the  views  enumerated  by  the  authors  of  this  paper.  They 
find  that  salicylic  acid  acts  differently  upon  yeast  when  added  to  worts  when  the 
yeast  and  acid  are  added  to  glucose  solutions.  Whilst  -5  gram  salicylic  acid  in 
1,000  cc.  sugar-solution  checks  the  action  of  15  grams  of  beer-yeast,  the  same 
quantity  of  the  acid  when  added  to  1,000  cc.  of  wort  has  no  apparent  influence 
upon  10  grams  of  yeast;  but  '5  gram  benzoic  acid  stops  the  action  of  1  gram  of 
preserved  yeast,  whilst  the  action  of  this  is  not  checked  by  -5  gram  salicylic  acid. 
The  key  to  the  explanation  of  this  was  found  in  the  fact  that  salicylic  acid  dis- 
