VARIETIES. 
181 
Chlorodyn. — Dr.  Ogden  requests  the  following  formula  to  be  used  in  pre  - 
ference  to  the  one  published  in  your  October  number — Chlorodyn  : — 
R  Chloroformyli,  f3vj. ;  iEther  Chlor.  f^j. ;  Tinct.  Capsic.  fgss. ;  Olei. 
Menth.  Pip.  gr.  ij. ;  Morphise  Hydrochlor,  gr.  viii. ;  Acid.  Hydrocyan. 
(Sch.)  gr.  xij. ;  Acid.  Perchloric,  gr.  xx. ;  Tinct.  Can.  Indicse,  fgj. ; 
Theriacge,  f^j- ;  Misce. 
The  importance  of  the  medical  profession  knowing  what  they  prescribe, 
needs  no  comment. — Ibid. 
Soluble  Glass. — Fuch's  soluble  glass  is  made  by  heating  together  15 
parts  pure  sand,  10  carbonate  of  potash,  and  1  of  charcoal.  This  can  be 
dissolved  in  4  or  5  parts  of  boiling  water,  which  should  be  then  evaporated 
to  the  specific  gravity  1-24. — Ibid,  Dec.  15,  1859. 
Proposed  New  Weights  for  Use  in  Pharmacy. — Mr.  Squire  laid  before  a 
recent  meeting  of  the  Pharmaceutical  Society  a  set  of  avoirdupois  weights, 
with  the  equivalent  in  grammes  marked  upon  each  weight.  He  had  pre- 
viously drawn  the  attention  of  the  society  to  the  comparative  values  of  troy 
and  metrical  weights,  but  as  it  was  now  probable  that  the  avoirdupois 
weight  would  be  adopted  in  the  forthcoming  Pharmacopoeia,  with  a  refer- 
ence to  the  equivalents  in  grammes,  it  was  desirable  that  pharmaceutists 
should  make  themselves  acquainted  with  the  relations  existing  between 
them. — Chemist  and  Druggist,  Dec.  15,  1859. 
Mauve  Dye. — This  exquisitely  beautiful  dye  for  silks  is  prepared  by 
taking  equivalent  proportions  of  sulphate  of  aniline  and  bichromate  of 
potash,  dissolving  them  in  water,  mixing,  and  allowing  them  to  stand  for 
several  hours.  The  whole  is  then  thrown  upon  a  filter,  and  the  black  pre- 
cipitate which  has  formed  is  washed  and  dried.  This  black  substance  is 
then  digested  in  coal-tar  naptha,  to  extract  a  brown,  resinous  substance  ; 
and  finally  digested  with  alcohol,  to  dissolve  out  the  coloring  matter,  which 
is  left  behind,  on  distilling  off  the  spirit,  as  a  coppery  friable  mass.  This 
is  the  dyeing  agent,  producing  all  the  charming  varieties  of  purples  known 
by  the  name  of  mauve,  which,  as  it  appears  to  us  somewhat  inappropri- 
ately, has  been  given  to  this  color.  The  particularity  of  these  purples 
consists  in  the  peculiar  blending  of  the  red  and  blue  of  which  they  are 
constituted.  The  permanence  of  these  hitherto  fugitive  combinations  is 
their  strongest  recommendation. — Ibid. 
Native  Country  of  the  Potato. — In  speaking  of  the  potato,  Dr.  Weddell 
has  recently  made  the  following  interesting  remarks ; — 
"  I  never  found  the  potato  in  Peru  so  circumstanced  as  to  satisfy  me 
that  it  is  really  wild  in  that  country.    Neither  do  I  believe  that  it  is 
