566 
ON  THE   USE  OP  SOLUBLE  GLASS. 
ARTIFICIAL  ROSE-WATER. 
By  Professor  Wagner: 
It  is  well  known  that  the  products  of  the  spontaneous  decompo- 
sition of  salicylate  of  potash  are  distinguished  by  a  peculiar  rose- 
like odor.  This  salt  is  obtained  by  boiling  oil  of  Winter-green  (the 
essential  oil  of  Gaultheria  procumbens),  which  may  now  be  ob- 
tained at  a  low  price,  with  solution  of  potash.  The  mother  liquor 
poured  away  from  the  paste  of  crystals  which  is  immediately  formed, 
possesses  a  penetrating  odor  of  roses,  and  when  distilled  with 
water,  furnishes  artificial  rose-water. — Chem.  Gazette,  Sept.  15, 
1858,  from  Wagner's  Jahresber.  uber  die  Fortschritte  der  chemis- 
chen  Technologie  fur  1859,  p.  260. 
ON  THE  USE  OF  SOLUBLE  GLASS. 
[Compiled  for  the  Druggists'  Circular.] 
Soluble  glass  is  prepared  by  fusing  a  mixture  of  15  parts  of 
quartz,  10  of  potash,  or  9  of  soda,  and  1  of  charcoal ;  in  its 
dry  state  it  is  clear,  colorless,  hard,  and  not  easily  fusible.  Gradu- 
ally added  to  boiling  water  in  the  form  of  fine  powder,  it  is  dis- 
solved after  some  time  in  5  or  6  times  its  weight  of  water  to  a 
syrupy  liquid.  The  same  solution  has  been  obtained  by  dissolv- 
ing quartz  directly  in  a  strong  solution  of  caustic  soda  under  a 
pressure  of  7  or  8  atmospheres. 
Common  chalk  previously  soaked  in  water,  and  afterwards  al- 
lowed to  remain  in  the  solution  for  a  few  days,  has  acquired 
such  a  hardness  that  it  cannot  be  scratched  with  the  finger  nail, 
and  may  be  readily  polished.  This  increase  of  hardness  pene- 
trates into  the  interior  of  the  piece  in  proportion  with  the  time 
allowed  for  the  reaction,  and  a  mass  is  thus  obtained  quite  un- 
susceptible to  the  influence  of  either  water  or  carbonic  acid. 
This  quality  of  the  soluble  glass  will  secure  it  a  vast  applica- 
tion for  the  hardening  and  preservation  of  porous  and  decaying 
building  stones,  and  walls  erected  with  such  material.  The  great 
painter,  Kaulbach,  has  the  merit  to  have  called  forth  a  new  pe- 
riod in  fresco  painting  by  the  use  of  the  soluble  glass  for  the 
fastening  of  his  paintings  upon  the  plaster  walls.  He  paints 
with  ordinary  water  colors,  or  mixes  them  with  a  weak  solution 
