276 
VARIETIES. 
of  the  chlorides  of  barium,  strontium,  or  copper,  with  an  equivalent  quanti" 
ty  of  a  warm  solution  of  chlorate  of  potassium.  The  clear  liquid  is  to  be 
poured  off  the  precipitated  chloride  of  potassium,  and  employed  for  the 
saturation  of  different  portions  of  the  gun-paper.  The  foregoing  makes 
an  admirable  lecture-experiment,  for  illustrating  the  colors  of  the  barium, 
strontium,  and  other  flames. — A.  II  Church. — Chem.  News,  Dec.  24,  1859. 
Bitumenized  Paper  Tubing. — An  experiment  was  recently  made  under 
the  great  clock  tower,  Westminister,  for  trying  the  strength,  by  hydraulic 
pressure,  of  a  new  description  of  tubing,  composed  of  bitumenized  paper, 
invented  by  M.  Jaloureau,  of  Paris.  M.  Jaloureau  is  a  contractor  for 
paving  Paris  and  other  towns  in  France  with  bitumenous  concrete.  It 
happened  in  the  course  of  his  experiments  that  some  paper  which  had 
been  coated  with  bitumen  was  laid  aside  in  a  coiled  form,  and  after  some 
time  it  became  very  stiff  and  solid.  Pursuing  the  idea  which  thus  acci- 
dentally occurred  to  him,  M.  Jaloureau  put  several  layers  of  bitumenized 
paper  round  a  cylinder,  and  submitting  them  to  internal  pressure,  he 
found  that  a  tube  a  quarter  of  an  inch  in  thickness  was  capable  of  resist- 
ing a  pressure  of  250  lbs.  to  the  square  inch.  The  municipal  authorities 
of  Paris  tried  these  tubes  for  the  conveyance  of  gas,  and  in  the  recent  ex- 
periments made  here  a  piece  of  tube  was  produced,  which,  though*  stated 
to  have  been  under  ground  in  Paris  as  a  gas  pipe  for  twelve  months,  had 
the  appearance  of  being  a  new  pipe.  The  tubes  subjected  to  the  pressure 
of  the  hydraulic  pump  bore  a  strain  of  250  lbs.  to  the  square  inch  without 
bursting,  which  is  more  than  they  would  be  ever  called  on  to  bear  in  ordi- 
nary use.  One  of  the  tubes,  half  an  inch  thick,  and  with  a  bore  of  two 
inches,  was  also  tested  by  weight,  and  it  only  gave  way  to  a  pressure  of 
428  lbs.  the  bearings  being  three  feet  apart.  It  was  stated  that  the  tubes 
might  be  submitted  to  a  temperature  of  160  degrees  of  Fahrenheit  without 
any  deterioration  of  the  material.  The  cost  of  the  tubing  is  said  to  be 
less  than  half  that  of  the  ordinary  iron  piping.  Messrs.  Paul  Joske  and 
Alexander  Young  are  the  patentees  of  the  invention  in  this  country. — 
Chem.  News,  Feb.  11,  1860. 
To  make  Paper  Waterproof. — Dissolve  8  ounces  of  alum  and  3|  ounces 
of  white  soap  in  4  pints  of  water  ;  in  another  vessel  dissolve  2  ounces  of 
gum  arabic  and  4  ounces  of  glue  in  4  pints  of  water.  Mix  the  two  solu- 
tions and  make  the  mixture  hot.  Immerse  the  paper  in  the  mixture,  and 
then  hang  it  up  to  dry  or  pass  it  between  cylinders. 
The  alum,  soap,  glue  and  gum  form  a  sort  of  artificial  covering  which 
protects  the  surface  of  the  paper  from  the  action  of  water,  and  to  a  certain 
extent  from  fire.  This  paper  will  be  very  useful  for  packages  which  may 
be  exposed  to  the  inclemency  of  the  weather. — Ibid,  from  Monitor  de  la 
Salud, 
