PHARAOH'S  SERPENTS 
61 
was  finding  himself  close  to  an  immense  fish  at  the  bottom  of 
the  sea.  Under  the  root  of  the  sponge  is  a  parasitical  substance 
of  a  caustic  nature.  This  often  bursts  when  the  sponge  is  sus- 
pended round  the  diver's  neck,  and  the  liquid  it  contains  causes 
deep  ulcers  in  his  flesh.  Before  exportation  the  sponges  are 
cleansed  and  spread  out  in  fields  to  dry.  Acres  of  them  may 
thus  be  seen  exposed  in  fine  weather.  Sponges  are  sold  by 
weight,  and  formerly  the  weight  used  to  be  increased  by  intro- 
ducing a  little  sand.  To  prevent  this  fraud,  the  merchants  in- 
sist upon  their  being  filled  with  as  much  sand  as  they  can  hold, 
and  as  this  amount  can  be  accurately  calculated,  it  is  deducted 
from  the  gross  weight. — Lond.  Chem.  $  Drug.,  Nov.  15,  1865. 
PHARAOH'S  SERPENTS. 
To  the  Editor  of  the  Pharmaceutical  Journal : 
Sir, — A  very  curious  toy  is  now  being  sold  in  Paris,  under  the 
name  of  Pharaoh's  Serpent.  As  this  toy  really  constitutes  an 
interesting  chemical  experiment,  perhaps  an  account  of  it  may 
prove  interesting  to  your  readers. 
It  consists  of  a  little  cone  of  tin-foil,  containing  a  white  powder, 
about  an  inch  in  height  and  resembling  a  pastille.  This  cone  is 
to  be  lighted  at  its  apex,  when  there  immediately  begins  issuing 
from  it  a  thick  serpent-like  coil,  which  continues  twisting  and  in- 
creasing in  length  to  an  almost  incredible  extent.  The  quantity 
of  matter  thus  produced  is  truly  marvellous,  especially  as  the 
coil  which  so  exudes  is  solid  and  may  be  handled,  although,  of 
course,  it  is  extremely  light  and  somewhat  fragile. 
Having  a  little  of  the  white  powder,  with  which  the  cones  are 
filled,  placed  at  my  disposal  by  a  friend,  I  submitted  it  to  analy- 
sis and  found  it  to  consist  of  sulphocyanide  of  mercury.  This 
salt,  when  heated  to  a  temperature  below  redness,  undergoes  de- 
composition, swelling  or  growing  in  size  in  a  most  remarkable 
manner,  and  producing  a  mixture  of  mellon  (a  compound  of  car- 
bon and  nitrogen)  with  a  little  sulphide  of  mercury.  The  result- 
ing mass  often  assumes  a  most  fantastic  shape,  and  is  sufficiently 
coherent  to  retain  its  form ;  it  presents  a  yellow  color  on  the  ex- 
