Chemical  Notes. 
( Am.  Jour.  Pharm. 
(      Feb.,  1881. 
l)iit  gm.  is  tlie  abbreviation  used.  Moreover,  in  writing  prescriptions 
in  the  old  system  of  weights  Roman  numerals  are  invariably  used  and 
jilaced  after  the  sign  which  represents  the  weight  unit,  thus :  gr.x,  ^j^ 
etc.,  whereas,  in  metric  prescrijjtions,  Arabic  numerals  are  used,  and 
invariably  placed  before  the  gm. 
Professor  Remington  calls  attention  to  the  fact  that  the  term  gramme 
is  now  in  use  by  millions ;  but  it  may  be  added  that  gram,  and  gramm. 
and  gramma  are  also  in  use  by  millions — g7rtm  being  the  term  used 
in  the  Scandinavian  countries,  and  now  to  a  great  extent  in  English- 
speaking  countries,  especially  in  the  United  States ;  gramm  is  the  term 
used  in  Germany,  and  gramma  in  Russia.  Other  terms,  derived  from 
the  same  root,  are  used  in  other  countries.  In  proposing  the  adoption 
of  the  gram  we  only  favor  the  adoption  of  the  shortest,  most  con- 
venient and  most  English  term,  one  tlftit  is  fully  as  well  understood 
as  gramme,  and  one  that  no  one  Avill  fail  to  recognize  at  once.  The 
same  may  be  said  of  meter  and         except  as  to  the  point  of  brevity 
Washington,  D.  C. 
CHEMICAL  NOTES. 
By  Pkofessor  Samuel  P.  Sadtler,  Ph.D. 
Inorgaxic'  Chemistry. — Existence  of  Ice  at  High  Temperatures^ 
— Prof.  Thos.  Carnelley  has  made  a  series  of  most  interesting  experi- 
ments on  the  conditions  of  melting  of  solids.  He  finds  that,  just  as  in 
order  to  convert  a  gas  into  a  liquid  the  temperature  must  be  below  a 
certain  point,  termed  the  critical  temperature,  of  the  substance,  no  mat- 
ter what  the  pressure,  so  in  order  to  convert  a  solid  into  a  liquid  the 
pressure  must  be  above  a  certain  point  which  he  calls  the  critical  pres- 
sure of  the  substance,  otherwise  no  amount  of  heat  will  melt  the  sub- 
stance. After  several  unsuccesful  attempts  he  was  so  fortunate  as  to- 
attain  the  most  perfect  success  in  the  case  of  ice,  obtaining  solid  ice  at 
temperatures  so  high  that  it  was  impossible  to  touch  it  without  burn- 
ing one's  self.  On  one  occasion  a  small  quantity  of  water  was  frozen 
in  a  glass  vessel  which  was  so  hot  that  it  could  not  be  touched  by  the 
hand  without  burning  it.  Ice  was  kept  for  considerable  lengths  of 
time  at  temperatures  far  above  the  ordinary  boiling  point,  and  even 
then  it  sublimed  away  without  any  previous  melting.  These  results 
were  obtained  by  maintaining  the  superincumbent  pressure  below  4*6- 
mm.  of  mercury,  i.  e.,  the  tension  of  aqueous  vapor  at  the  freezing- 
