ON  A  SAFETY  LAMP  FOR  LABORATORY  USE. 
217 
the  presence  of  strychnia,  yet  his  evidence  of  the  masking  effect 
of  morphia,  taken  in  connection  with  the  fact  of  the  patient 
having  taken  morphia  just  before  death,  and  the  strong  moral 
evidence,  caused  the  conviction  of  the  accused,  who  subsequently 
made  a  full  confession  of  the  crime. 
The  remainder  of  Dr.  Reese's  paper  is  occupied  with  a  de- 
tailed explanation  of  the  best  modes  of  applying  the  color-test, 
with  the  value  of  bitterness  as  a  collateral  test,  with  the  physio- 
logical or  frog  test  of  Dr.  Marshall  Hall,  and  with  the  micro- 
scopy of  strychnia,  but  the  space  at  command  is  too  small  to 
insert  it  here;  and  the  reader  desirous  of  pursuing  the  subject,  is 
referred  to  the  original  paper  before  noted,  and  to  two  papers 
in  this  Journal  published  in  November,  1861. 
ON  A  SAFETY  LAMP  FOR  LABORATORY  USE. 
By  C.  M.  Warren. 
The  danger  attending  the  distillation  of  highly  inflammable 
liquids,  in  glass  retorts,  over  an  open  flame, — and  other  manipu- 
lations of  similar  nature, — as  commonly  practised  in  labora- 
tories, has  probably  been  felt  by  every  one  who  has  made  such 
experiments.  By*  the  exercise  of  due  precaution,  the  chances 
for  accident  under  such  circumstances  may,  doubtless,  be  greatly 
reduced;  yet  the  consequences  which  may  result  from  a  single 
mishap,  are  liable  to  be  so  serious  (as  the  fate  of  the  lamented 
Mansfield  gives  painful  evidence,  although,  I  believe,  he  was 
using  a  metallic  retort  at  the  time  of  the  fatal  occurrence,)  that 
it  seemed  to  me  desirable  to  devise  means  by  which  such  experi- 
ments may  be  conducted  with  safety;  especially  as  the  chemist 
has  so  frequently  to  resort  to  protracted  fractional  distillation 
of  complex  mixtures  of  inflammable  substances,  as  his  only 
means  by  which  to  effect  a  separation. 
I  find  that  a  lamp  may  be  constructed  on  the  principle  of 
Davy's  safety-lamp  for  miners,  so  as  to  afford  the  important 
desideratum  of  safety,  and  at  the  same  time  combine  utility  and 
convenience  for  general  use,  in  cases  where  a  broad  open  flame 
and  a  diffused  heat  are  desirable.  Simple  modes  of  applying 
the  principle  will  readily  suggest  themselves. 
It  is  only  requisite  that  the  flame  should  be  properly  enclosed, 
