Am.  Jour.  Pharm. 
June,  1893. 
Method  of  Chemical  Synthesis. 
313 
per  cent.  H2S04  and  solidifying  at  —  5 6°,  was  brought  when  in 
the  solid  condition  and  at  —  1250  into  intimate  contact  with 
finely  powdered  sodium  hydroxide,  also  at  —  1250,  and  the  two 
strongly  compressed  without  any  sign  of  chemical  change  occurring. 
The  passage  of  electric  sparks  through  the  mass  only  causes  action 
to  take  place  in  the  path  of  the  sparks,  but  this  action  is  not  com- 
municated to  the  rest  of  the  mixture.  On  warming,  action  suddenly 
commences  at  —  8o°,  the  heat  evolved  and  abrupt  change  of  tem- 
perature causing  breakage  of  the  vessel  containing  the  mixture. 
With  sulphuric  acid  containing  35  per  cent.  H2S04  and  solidifying 
at  —  88°,  similar  results  were  obtained.  Potassium  hydroxide 
employed  in  place  of  sodium  hydroxide  remains  in  like  manner 
unacted  on  below  —  900.  Concentrated  ammonia  and  sulphuric 
acid  do  not  act  at  all  on  one  another  below  —  8o°  ;  above  this 
temperature,  a  limited  action  takes  place  under  the  action  of  electric 
sparks,  and  at  — 6o°  to  — 65 0  complete  action  suddenly  occurs. 
Sulphuric  acid  and  common  salt  do  not  react  below  —  500  ;  from 
—  500  to  —  25 0  there  is  a  limited  action,  and  then  complete  action 
occurs.  With  the  carbonates  of  calcium  and  sodium  and  35  per 
cent.  H2S04,  there  is  no  action  at  —  8o°.  The  first  bubbles  of  gas 
make  their  appearance  at  —  560  with  sodium  carbonate,  and  at 
—  5 2°  with  calcium  carbonate,  and  the  reaction  becomes  turbulent 
at  —  1 50  with  calcium,  and  at  —  300  with  sodium  carbonate.  All 
other  carbonates  behave  similarly.  With  nitric  acid  in  place  of 
sulphuric  acid,  similar  results  were  obtained  in  all  the  above  cases, 
chemical  action  commencing,  however,  at  a  slightly  lower  tempera- 
ture in  each  case.  Metallic  sodium,  when  brought  into  contact 
with  aqueous  alcohol,  containing  84  per  cent,  alcohol,  at  — 78 °, 
undergoes  no  change.  Action  only  commences  at  —  480,  and  then 
proceeds  briskly.  Sodium  and  35  per  cent.  H2S04  may  be  mixed 
at  — 85 0  without  any  action  occurring,  but,  when  heated  up  to 
—  500,  a  violent  action  suddenly  commences,  the  hydrogen  evolved 
inflaming  spontaneously.  Metallic  potassium  acts  in  a  similar 
manner,  but  in  this  case  change  sets  in  at  — 68°  instead  of  — 500. 
If  sulphuric  acid  and  an  alcoholic  solution  of  barium  chloride  are 
mixed  at  — 85 °,  no  change  occurs,  a  precipitate  first  appearing 
when  the  solution  is  heated  to — 700.  At— 400  the  reaction  is 
complete.  Alcoholic  silver  nitrate  and  hydrochloric  acid  were  mixed 
at  —  1250  without  reaction.   At  — 900  action  commenced,  and  was 
