148 
CADMIUM. 
pots  and  similar  domestic  utensils  are  made.  It  is  owing  to  a 
mordant  of  tin  that  the  dyer  produces  the  fine  scarlet  cloth  so 
famous  as  the  Royal  and  Military  color  of  this  country.  In 
many  other  ways  we  could  show  how  very  useful  tin  is  ;  but  it 
is  enough  for  us  to  state  that  England  is  the  tin-plate  manufac- 
turer for  the  whole  world.  — CAm.  News,  Bee.  1860,  from 
Piesse's  Laboratory  of  Chemical  Wonders. 
ON  THE  DETECTION  OF  TARTAE  IN  VINEGAR. 
By  M.  L.  Dusart. 
The  inquiry  instituted  by  M.  Dusart  is  founded  on  the  solu- 
bility of  potassio-tartrate  of  iron.  The  vinegar  is  evaporated  to 
the  consistence  of  extract,  a  little  of  which  is  dissolved  in  water, 
a  few  drops  of  solution  of  perchloride  of  iron  are  added,  and 
the  whole  is  boiled,  and  then  suflScient  solution  of  potash  to  give 
the  liquid  an  alkaline  reaction  is  poured  in,  then  it  is  filtered. 
If  sulphuretted  hydrogen  indicates  the  presence  of  iron  in  the 
liquid,  and  produces  no  reaction  in  an  alkaline  liquor  prepared 
with  extract  of  vinegar  without  the  addition  of  chloride  of  iron, 
we  may  infer  the  presence  of  tartaric  acid,  or  at  least  the  neces- 
sity for  a  stricter  search,  which  is  quite  superfluous  if  the  re- 
agent does  not  color  the  liquid. 
No  similar  results  are  obtainable  from  mineral,  oxalic,  malic, 
or  citric  acids.  A  counter-proof  is  always  useful,  because  acci- 
dental substances,  tartaric  acid  for  instance,  dissolve  the  sesqui- 
oxide  of  iron  in  an  alkaline  medium. — Chem.  News,  Dee.  1860, 
from  Repertoire  de  CJiimie. 
CADMIUM. 
By  B.  Wood,  M.  D, 
The  properties  of  cadmium  appear  to  have  been  less  clearly 
determined  by  chemists  and  metallurgists  than  those  of  most 
other  metals.  Discrepancies  exist  in  regard  to  it,  while  some  of 
its  most  remarkable,  if  not  most  useful,  properties  are  not  at  all 
noticed,  at  least  by  the  generality  of  authors,  even  when  expli- 
cit and  elaborate  as  to  similar  properties  possessed  by  other 
