'^'"'FibTx^sJ""'}  Chemical  Notes,  83 
.account  of  the  variability  of  the  product.  Undoubtedly  this  variability 
was  not  the  result  of  the  insolubility  of  the  subcarbonate  alone,  but 
may,  more  or  less,  have  been  the  result  of  defective  manipulation — as^ 
for  instance,  the  non-  or  improper  application  of  heat  to  effect  solution. 
The  vi^riter  of  this  well  remembers  a  very  expeditious  and  easy  method 
followed  by  several  apothecaries  of  this  city  ;  but  the  resulting  tincture 
does  not  reach  the  standard  of  the  Pharmacopceia  by  50  per  cent.  It 
is  :  Place  the  subcarbonate  of  iron  in  a  bottle  of  sufficient  size,  pour 
on  the  hydrochloric  acid,  shake  frequently  until  effervescence  ceases, 
add  the  alcohol  and  filter.  This  finishes  the  tincture.  An  ounce  of 
the  tincture  made  in  this  manner  treated  with  ammonia  in  excess,  and 
the  precipitate  washed,  dried  and  ignited,  was  found  to  weigh  I2*8  grs. 
Lo-welly  N.  St.  LouiSy  January,  1880. 
CHEMICAL  NOTES. 
By  Prof.  Samuel  P.  Sadtler. 
Inorganic  Chemistry.  —  Volatility  of  Platinum.  —  Victor  Meyer 
notices  the  recent  statements  of  F.  Seelheim  as  to  the  volatility  of  plati- 
num (this  Journal,  current  volume,  p.  18),  and  shows  that  they  have  no 
applicability  to  his  results  on  the  vapor-density  of  chlorine  at  high  tem- 
.peratures.  In  these  experiments  the  decomposition  of  the  platinous 
■chloride  left  the  platinum  in  the  form  of  a  small  stick  of  coherent 
platinum  sponge  of  exactly  the  shape  of  the  little  glass  bulb  used  for 
the  platinous  chloride.  Moreover,  the  weight  of  the  platinum  left  was 
almost  absolutely  the  weight  required  by  calculation  of  the  co.mposi- 
tion  of  the  platinous  chloride.  Again,  the  results  gotten  where  iodine 
was  used  were  just  as  anomalous  as  those  gotten  with  chlorine,  and  of 
course  the  iodine  was  used  from  the  beginning  as  pure  iodine.  So  the 
Victor  Meyer  results  remain  as  yet  unexplained,  the  author  giving  no 
further  information  and  expressing  no  views  as  to  the  reason  of  the 
variance  from  normal  density. — Ber,  der  Chem.  Ges.^  xii,  p.  2202. 
Crystallization  of  Carbon. — At  a  meeting  of  the  Glasgow  Philosophi- 
cal Society,  on  Wednesday,  Dec.  24th,  1879,  Mr.  James  Mactear 
stated  that  he  had  obtained  transparent  crystals  of  the  form  and  refrac- 
tive power  of  diamonds.  They  resisted  acids,  alkalies  and  the  intense 
heat  of  the  blow-pipe,  and  scratched  glass.  Prof.  Maskelyne  (Dec. 
31)  found  these  crystals  not  to  scratch  either  topaz  or  sapphire,  not  to 
