344 
NEW  ELECTRICAL  MACHINE. 
copal  varnish,  on  drying,  it  does  not  show  near  the  same  power, 
and,  what  is  rather  difficult  to  understand,  after  the  lapse  of  a 
few  days,  seems  no  more  electric  than  wet  wood,  while  the  simple 
wood  remains  so.    Oil,  I  believe,  is  supposed  to  attract  a  small 
quantity  of  moisture  from  the  atmosphere,  but  how  can  it  do  so 
when  the  varnish  is  dry  and  the  oil  solid  ?    Machines  formed  of 
wooden  discs  coated  in  this  manner  were  described  in  the  time 
of  Ingenhouz,  and  that  was  my  original  intention,  when,  on 
taking  the  piece  of  wood  from  the  fire,  I  thought  I  would  just 
see  if  it  were  capable  of  itself  (before  varnishing)  of  showing 
attraction  on  rubbing,  when  lo  !   a  strong  spark  flies  off.  I 
recollect,  some  ten  or  twelve  years  ago,  when  at  school,  (reading 
of  the  power  of  brown  paper,)  attempting  to  form  a  cheap 
machine  of  wood,  covered  with  brown  paper,  and  thought  it  very 
hard  I  couldn't  get  the  slightest  spark,  heat  or  rub  how  I  might, 
little  imagining  at  the  time  that  the  wood  only  wanted  drying  to 
form  itself  the  best  substance.    As  a  rubber,  I  employ  catskin ; 
but  either  (unvarnished)  silk,  or,  still  better,  "  vulcanized  India- 
rubber,"  answer  equally  well.    I  have  late  mounted  my  machine 
with  wooden  discs,  in  the  place  of  ebonite  ones,  and  the  effects 
must  be  seen  to  be  believed.    Now,  if  this  is  anything  new  to 
you,  sir,  perhaps  you  might  wish  to  see  such  an  instrument,  in 
which  case,  you  might  call  any  day  between  ten  and  four  o'clock, 
or  else  it  might  be  sent  to  your  address.    Can  you  suggest  any 
means  of  rendering  wood  permanently  as  well  as  absolutely 
dry?    I  carry  on  the  "baking"  or  drying  till  the  surface  is 
slightly  colored,  but  not  "  carbonized,"  in  which  case,  at  the  end 
of  two  months,  it  appears  equally  electric  as  the  first  day,  and 
that  in  spite  of  a  small  quantity  of  steam  when  put  before  the 
fire. 
I  am,  &c, 
F.  E.  S.  Jerningham. 
52  Cambridge  Terrace,  March  19. 
— Lond.  Chem.  News,  March  23,  1866. 
New  Electrical  Machine — Electricity  of  Wood. 
The  communication  from  Mr.  Jerningham,  which  we  printed  in 
our  number  for  March  23,  was,  we  are  sorry  to  find,  not  intended 
