530 
APPARATUS  FOR  THE  USE  OF  GAS  IN  PHARMACY. 
and  in  an  immense  variety  of  processes  in  the  arts,  and  occa- 
sionally in  cooking,  and  the  warming  of  apartments,  this  widely 
diffused  fuel  is  employed. 
It  would  extend  this  essay  too  much,  and  be  foreign  to  its  im- 
mediate object,  if  I  should  attempt  a  description  of  the  various 
forms  of  gas-heating  apparatus  in  common  use  ;  a  notice  of  many 
of  these  will  be  found  in  the  late  edition  of  my  work  on  Phar- 
macy. Nearly  all  are  constructed  on  the  principle  of  introdu- 
cing atmospheric  air  with  the  gas  into  a  cylinder,  at  the  top  of 
which  it  is  lighted  over  wire  gauze.  Some,  of  recent  construc- 
tion, promote  the  thorough  admixture  of  the  gas  with  air,  by 
modifications  of  the  shape  of  the  cylinder,  or  by  forcing  a  draft 
of  air  through  it ;  others  by  combining  several  small  cylinders 
(Bunsen's)  into  one  stove,  or  by  terminating  the  ordinary  Bun- 
sen  burner  with  a  perforated  disc,  derive  increased  heat  from 
the  jet  of  gas,  though  often  with  a  greatly  increased  consump- 
tion. 
This  cut  represents  McGlensy's  patent,  which  is  a 
modification  of  the  fiunsen  burner.  Figs.  1  and  2 
show  a  simple  brass  cylinder,  with  attachment  for 
the  introduction  of  the  gas  and  a  current  of  atmos- 
pheric air.  The  orifice  of  the  burner  is  about  i  of 
an  inch  above  the  top  of  the  holes  for  the  admission 
of  the  air,  an  important  feature  in  determining  the 
degree  of  force  of  the  upward  column  of  mixed  air 
and  gas.  When  this  burner  is  used  as  a  blow-pipe,  or  for  any 
purpose  requiring  a  concentrated  heat,  the  gas  is  ignited  at  the 
top  of  the  cylinder,  and  the  flame  burns  with  a  slight  blue  color, 
and  without  smoke,  rising  under  the  full  pressure  three  or  four 
inches  above  the  top. 
The  other  figure  represents  a  perforated  disc  for  diffusing  the 
flame,  which  constitutes  McGlensey's  improvement.  This  is  an 
advantage  for  heating  liquids  in  vessels,  or  cast  iron  plates  such 
as  are  used  for  batter  cakes,  for  heating  sad-irons?  or  for  radia- 
ting heat,  as  in  warming  apartments.  These  burners  are  highly 
recommended  by  many  who  use  them,  and  are  of  a  variety  of 
sizes,  burning  from  four  to  twelve  or  fifteen  cubic  feet  per  hour, 
It  is  claimed  that  one  of  them  will  boil  a  quart  of  water,  in  a  tin 
I 
