84 
ON  NITROGLYCERINE  OR  GLO  NOINE. 
added  to  the  above-described  clear  fluid  after  the  addition  of  the 
acid,  even  when  this  has  been  diluted  with  double  the  quantity 
of  water,  causes  it  to  become  opalescent,  and  even  to  coagulate. 
The  former  appearance  is  produced  even  after  the  addition  of  a 
few  drops  of  the  solution  of  carbonate  of  ammonia ;  the  latter, 
when  the  quantity  added  amounts  to  about  one-eighth  of  that 
of  the  solution  of  the  silicate. 
From  Liebig's  experiments  it  appears  that  no  chemical  com- 
pound of  silica  and  ammonia  exists ;  the  ammonia  found  by 
Struckmann  in  gelatinous  silica  is  retained  by  this  in  the  same 
manner  as  by  porous  bodies,  such  as  alumina. 
Way  has  observed  (Journ.  Agric.  Soc,  xii.  p.  124)  that  clay, 
which,  as  is  well  known,  absorbs  ammonia,  also  possesses  the 
power  of  extracting  the  ammonia  from  water  containing  it. 
This  property,  says  Liebig,  explains  why  drainage-water  seldom, 
if  ever,  contains  traces  of  ammonia;  the  ammonia  is  not  washed 
out  of  fields  with  a  clayey  soil.  Way  has  explained  this  by  the 
supposition,  that  ammonia,  like  lime,  is  capable  of  entering  into 
the  composition  of  the  double  silicate  of  alumina  and  lime  con- 
tained in  the  soil,  by  displacing  the  lime ;  he  has  also  expressed 
the  opinion,  that  such  double  silicates  of  alumina  and  ammonia 
furnish  plants  with  the  ammonia  required  for  the  production  of 
their  nitrogenous  constituents.  Liebig  expresses  himself  very 
decidedly  in  opposition  to  this  explanation  of  the  fact,  the  sili- 
cates of  alumina  absorbing  ammonia  like  other  porous  bodies, 
(sea-sand,  ahestos,  Faraday),  and  also  against  this  supposed 
source  of  nitrogen  for  plants  Chem.  Caz.  Oct.  1,  1854,  from 
Liebig's  Annalen. 
ON  NITROGLYCERINE  OR  GLONOINE. 
By  J.  E.  De  Vrij. 
Nitroglycerine  was  first  employed  in  medicine  in  America, 
under  the  name  of  glonoine.  The  author,  who  repeatedly  paid 
attention  to  this  body  since  its  discovery  by  Sobrero,  gives  the 
following  prescription  for  its  preparation,  which  he  has  found 
most  successful.  100  grms.  of  glycerine,  of  spec.  grav.  1*262, 
dried  at  302°  F.,  are  poured  gradually  into  200  cub.  centims.  of 
monohydrated  nitric  acid,  which  is  to  be  cooled  to  14°  F.  by  a 
