AmFe0bur-x8P76arm-}    Development  of  the  Chemical  Arts.  79 
tain  various  alkaloids,  or  else  that  the  alkaloid  present  is  extremely 
alterable.  Duquesnel  has  suggested  that  "  aconitia "  is  probably  a 
glucoside  ;  this  view  is  quite  in  harmony  with  the  results  obtained, 
different  specimens  being  not  improbably  mixtures  of  the  glucoside  and 
the  product  of  its  deglucosation.  "  Pseudaconitina,"  when  left  in  con- 
tact with  water  and  emulsin,  emits  an  unpleasant  fermentative  odor,  and 
partially  dissolves,  the  solution  containing  a  salt  giving  ajeddish  colora- 
tion with  ferric  chloride,  presumably  an  acetate  ;  no  glucose,  however, 
could  be  detected  in  the  liquid  at  any  stage  of  the  action. — Journ.  Chem. 
Soc.  [Lond.],  Dec,  1875,  from  Tear-book  of  Pharmacy  and  Pharm.  Con/. 
Trans.,  1875. 
REPORT  ON  THE  DEVELOPMENT  OF  THE  CHEMICAL  ARTS  DUR- 
ING THE  LAST  TEN  YEARS.* 
BY  DR.  A.  VV.  HOFMANN. 
(Continued  from  p.  35.) 
Tessie  du  Motay  and  Marechalf  have  introduced  a  valuable  modification  into 
practice,  as  they  require  no  steam-boiler  for  the  manufacture  of  the  water-gas,  and 
thus  economise  fuel,  whilst  the  wear  of  the  simplified  apparatus  is  considerably  re- 
duced. They  heat  coal  with  soda,  hydrate  of  lime  or  of  baryta  in  iron  retorts,  and 
thus  decompose  the  combined  water  of  these  bases,  which  is  then  freed  from  car- 
bonic acid  in  the  ordinary  manner  This  procedure  has  been  adopted  by  the  New 
York  Oxygen  Company,  who,  in  the  manner  described  above,  sell  water-gas  at  the 
enormous  price  of  2  cents  per  cubic  foot,  or  1  cubic  metre  for  3s.  6&.%  The  mix- 
ture of  lime  and  anthracite  is  heated  in  retorts,  such  as  those  described  above  under 
Tessie  du  Motay 's  method  of  preparing  oxygen.  The  decomposition  takes  place 
at  a  red-heat,  according  to  the  equation — C-r-Ca0-f2H20=CaC03-r-2H2,  and  lasts 
about  fifteen  minutes.  Thereupon  hydrate  of  lime  is  reformed  by  passing  steam 
over  the  heated  mass.  The  carbon  is  not  exhausted  until  after  three  weeks,  and  is 
then  replaced  by  a  fresh  supply  of  anthracite. 
That  coal-gas  contains  large  quantities  (30  to  50  per  cent.)  of  free  hydrogen,  and 
that  the  proportion  of  this  ingredient  rises,  the  higher  the  temperature  of  the  retorts 
in  preparing  the  gas,  has  long  been  known.  Tessie  du  Motay  and  Marechal,  whilst 
introducing  the  above-described  procedure,  have  taken  advantage  of  this  circum- 
stance, and  have  passed  coal-gas  over  lime  in  order  to  resolve  it  into  carbon,  hydro- 
carbons boiling  at  high  temperatures,  and  large  quantities  of  hydrogen.  At  the 
same  time  E.  Vial$  adopted  the  same  method,  and  has  doubled,  and  even  trebled, 
the  yield  of  gas  by  "  decarburation."  Schinz||  doubts  the  industrial  value  of  this 
process,  on  account  of  the  outlay  for  fuel,  and  calculates  that  the  decompostion  of 
*  "  Berichte  uber  die  Entwickelung  der  Chemischen  Industrie  Wfihrend  des  Letzten  Jahrzehends." 
f  "Bull  Soc  Chim.,"  1868,  i.,  334. 
%  H.  Vogel,  "  Ber.  Chem.  Ges.,"  iii.,  901. 
§  Vial,  "Genie  Industrie!,"  1869.    "  Ding!.  Pol.  J.,"  cm'.,  382. 
||  Schinz,  "  Dingl.  Pol.  J.,"  cii.,  388. 
