An  Evening  with  the  Microscope.* 
(Continued  from  page  S3.) 
We  now  come  to  the  sub-stage  illuminators,  of  which  the 
mirror  is  about,  the  most  important  and  indispensable;  and 
beyond  saying  that  one  side  is  flat  for  use,  when  there  is 
abundance  of  daylight,  the  other  side  concave  for  artificial  light. 
The  achromatic  condenser,  which  is  a  combination  of  lenses,  is 
used  in  the  sub-stage  in  connection  with  the  mirror  and  bulls-eye 
condenser  for  more  fully  illuminating  the  structure  of  the 
object.  This  condenser  is  fitted  with  a  diaphragm  or  perfo¬ 
rated  plate,  which,  revolves  for  the  purpose  of  increasing  or  dimi¬ 
nishing  the  light  as  desired.  For  dark-field  illumination  the  Wen- 
ham  Parabola  produces  some  most  beautiful  effects.  The  light  is 
reflected  from  the  mirror  through  the  cone  shaped  parabola  at 
an  oblique  angle,  and  is  reflected  on  to  the  object  on  the  stage. 
To  prevent  the  light  passing  direct  to  the  object,  there  is  a 
stop  with  a  wire  and  screw  thread  to  regulate  it,  which  cuts  off 
the  direct  rays  and  causes  the  light  to  be  reflected.  The  object 
is  thus  illuminated  on  a  beautiful  dark  ground. 
For  oblique  illumination,  some  most  beautiful  effects  are 
produced  by  the  use  of  Amici’s  prism,  which  fits  in  the  sub-stage, 
and  when  using  this  prism, the  object  should  be  rotated  by  the 
stage  fitting.  Nashet’s  prism  is  also  a  useful  fitting  for  similar 
effects,  and  this  can  be  rotated  without  moving  the  stage-fitting. 
The  illuminations  of  transparent  subjects  thus  obtained  on  a 
dark  ground  are  most  delightful,  particularly  in  Foraminifera 
and  Polycistina,  as  'the  shells  appear  most  beautifully  trans¬ 
parent;  but  there  are  many  others  equally  delightful  when 
viewed  through  these  prisms. 
We  will  now  turn  our  attention  to  polarised  light  illumina¬ 
tion,  which  produces  .most  wonderful  effects,  and  frequently 
assists  in  accurate  determination  of  structure,  when  no  other 
method  is  of  any  avail j  It  is  produced  by  the  application  of 
Nicol’s  prisms  of  Iceland  spar  and  selenites.  The  analyser 
should  be  fixed  above  the  objective,  whilst  the  polarizer 
is  fixed  in  the  sub-stage,  and  both  should  be  so  that  they  can 
be  easily  rotated  ;  the  effect  produced  by  these  fittings  is  simply 
marvellous.  We  all  know  Epsom  salts,  white  as  they  are,  but 
to  see  them  under  polarized  light  is  simply  astonishing  to  the 
uninitiated  microscopist,  and  by  the  use  of  these  darkers 
(selenite  plates)  thirteen  distinct  colours  can  be  produced. 
There  are  various  methods  of  holding  subjects  on  the  stage 
during  examination.  The  mineral  holder,  as  its  name  implies, 
is  for  small  pieces  of  minerals;  the  three-pronged  forceps  for 
holding  irregular  shaped  objects,  and  the  stage  forceps  for  hold¬ 
ing  small  objects,  these  last  two  fit  into  a  small  socket  on  the 
stage.  The  brass  forfreps  are  principally  used  for  collecting 
Algae,  Ac.,  both  in  salt  and  pond  water,  as  they  do  not  rust.  The 
opaque  disk  revolver,  and  forceps  with  disks  are  used  for 
examining  minute  objects,  which  should  be  gummed  to  the  disk 
and  rotated  under  the,  objective  by  means  of  the  fine  chain, 
so  that  all  sides  of  the  subject  can  be  examined  very  easily. 
The  compressors  cf  three  different  kinds  are  for  holding  insects 
and  other  objects  in  a  fixed  position  while  being  examined ; 
the  three  live  boxes  are  for  a  similar  purpose,  only  the  insect 
can  be  allowed  to  walk  about  if  desii’ed.  The  set  of 
three  dipping  tubes  are  for  catching  small  insects  or 
animalcules  in  ponds,  Ac.  The  glass  trough  is  intended 
for  holding  large  insects  or  other  objects  in  water 
while  being  examined.  The  stage  micrometer  in  brass 
is  to  assist  in  measuring  objects.  The  Maltwood  finder  is 
divided  by  horizontal  aud  vertical  lines  into  2,500  squares,  and 
used  for  very  minute  objects.  The  frog-plate,  with  bag 
attached,  is  used  for  examining  the  circulation  of  blood  in  a 
frog’s  foot.  The  animal  is  put  in'  the  bag  and  securely  fastened 
to  one  end  of  the  plate,  while  some  pieces  of  silk  are  fastened 
to  each  claw  of  one  foot,  the  latter  being  stretched  out  over 
the  circle  cf  glass  in  the  plate,  and  then  secured  to  the  pins 
underneath,  to  hold  it  in  position.  It  is  then  secured  to  the 
stage  of  the  instrument,  and  by  means  of  the  light  reflected 
from  the  mirror,  the  circulation  cf  the  blood  is  seen  with 
beautiful  effect.  The  pair  of  glass  slips  with  ledge  are  for 
examining  drops  of  blood  and  other  fluids,  Ac. 
To  have  the  full  enjoyment  of  the  microscope  it  is  very 
desirable  to  have  a  table  that  will  revolve,  so  that  you  are  able 
to  invite  a  friend  to  share,  your  enjoyment  without  the  weari¬ 
some  work  of  getting  on  and  off  your  seat  to  make  room  for 
him  to  look  down  upon  the  instrument.  The  revolving  part  of 
this  table,  with  race  for  bicycle  balls  to  run  in,  and  thumb 
screws,  are  my  own  invention.  It  can  be  used  to  revolve,  or 
as  a  fixed  top  table,  around  which  six  people  can  comfortably 
seat  themselves,  and  view  the  various  subjects  as  long  as 
desirable,  without  the  annoyance  of  moving.  I  should  say 
that  many  of  these  fittings  are  modern  inventions  which  I  have 
purchased  since  I  came  into  possession  of  the  instrument. 
(To  be  concluded.) 
t*  Pappr  raatl  by  Mr.  J.  OHerhead  at  a  meeting  of  the  Wimbledon  and 
District  Gardeners’  Mutual  Improvement  Society,  Febiuary  17th.  1902.  The 
subject  being  again  brought  forward  on  March  17th,  after  a  discussion  on 
Roses  in  pots. 
njA  .  i  >t; .  -jJk  ,i _  : 
New  Park  for  London 
The  Parks  and  Open  Spaces  Committee  of  the  County  Council 
have  an  opportunity  of  acquiring,  for  the  sum  of  £25,000,  the 
house  and  grounds  known  as  Avery  Hill,  Eltham.  The  land  has 
an  area  of  eighty-four  acrq^  and  contains  a  mansion  with  a 
picture  gallery  and  a  large  park. 
Testimonial  to  the  Rev.  H.  H.  D  Ombrain. 
All  the  friends  and  admirers  of  our  Nestor  of  Rosarians  will 
rejoice  to  hear  that  the'  D’Ombrain  Purse  Fund,  which  was 
inaugurated  by  the  Dean  of  Rochester  last  spring,  is  now  com¬ 
pleted,  and  amounts  to  the  substantial  sum  of  £370.  Those  who 
know  of  the  sacrifices  made  by  the  presentee  in  the  cause  cf  the 
Rose,  and  of  the  anxieties  which  have  weighed  upon  him  latterly 
will  be  pleased  to  know  cf  the  success  of  the  appeal  made  by  the 
Dean. 
Kliled  in  an  Orchard. 
A  schoolboy  at  Longdon,  a  rural  district  of  Worcestershire, 
came  by  his  death  in  an  unusual  manner.  Taking  one  of  the 
farm  horses,  he  rode  into  an  orchard  and  passed  under  an  Apple 
tree  to  pick  some  of  the  fruit.  While  he  was  in  the  act  of  reach¬ 
ing  for  the  Apples  the  horse  must  have  moved  on,  with  the  result 
that  the  boy’s  jacket  collar  was  caught  by  a  broken  bough.  He 
thus  became  suspended  in  the  air,  and,  being  unable  to  extricate 
himself  or  make  his  cries  heard,  he  remained  there  until  he  died. 
His  mother  found  him  hanging  dead. 
Rainfall  at  Temple  House  Gardens. 
The  register  of  rainfall  for  the  month  of  July  was  0.92in,  the 
highest  maximum  temperature  was  83deg  on  the  14th  and  the 
lowest  minimum  was  38deg  on  the  11th.  Rain  fell  on  eleven  days  ; 
on  the  26th  and  27th  there  was  a  rough  S.W.  gale  which  stripped 
branches  of  green  leaves  from  the  trees,  completely  covering  the 
pleasure  grounds  and  gardens  with  rubbish.  The  rainfall  for 
July,  1901,  was  2.38in,  the  highest  maximum  temperature  was 
88deg  on  the  18th  and  19th,  and  the  lowest  minimum  47deg  on 
the  7th  of  the  month.— G.  Groves. 
English  Plums  Scarce. 
The  gale  which  swept  the  .country  last  week  played  havoc  with 
some  of  the  fruit  crops.  Plums  and  Apples  appear  to  have  been 
principally  affected.  The  trees  in  many  cases  were1  literally 
stripped  of  fruit.  At  Covent  Garden  it  is  stated  that  the  Plum 
crop  this  year  is  in  a  very  had.  state,  consequently  prices  for 
English  Plums  are  somewhat  high ;  but  ample  supplies  are  forth¬ 
coming  from  California.  A  large  consignment  of  Californian 
Plums  has  been  delivered  in  England  and  are  selling  at  8d.  per 
lb.  Owing  to  cold  storage  the  fruit  when  delivered  here  is  as 
fresh  as  when  picked  from  the  'trees  oyer  7,000  miles  away. 
West  Indian  Fruit. 
A  direct  service  of  fruit  steamers  between  the  West  Indies 
and  Manchester,  belonging  to  Messrs.  Elder  and  Fyffes,  Limited, 
has  been  inaugurated,  so  far  as  concerns  Manchester.  The 
Chickahoming,  the  first  steamer  of  the  service,  reached  the  Ship 
Canal  docks  on  Sunday  night,  bringing  30,000  bunches  of  Bananas 
from  Jamaica.  Mr.  A.  Rodger  Ackerley,  a  director  of  the  firm, 
who  presided,  responded  to  the  toast.  He  said  the  opening  of 
the  new  service  had  been  successful,  for  they  had  never  had  a 
cargo  of  fruit  landed  in  England  in  such  perfect  condition  since 
they  began  its  importation  to  Bristol  eighteen  months  ago.  Their 
chief  difficulty  at  present  was  that  Manchester  men  did  not  buy 
many  Bananas.  Manchester,  in  fact,  seemed  to  have  a  prejudice 
against  the  Banana  which  was  not  shared  by  other  towns.  They 
hoped,  however,  soon  to  have  sufficient  trade  to-  demand  a  weekly 
instead  of  a  fortnightly  service.  Mr.-  J.  K.  Bythell,  chairman  of 
the  Ship  Canal  Company,  said  that  during  tlie  morning  13,000 
bunches  of  the  fruit  had  been  despatched  from  the  docks,  and  by 
the  evening  all  the  cargo  would  be  away.  Fifteen  waggonloads 
had  been  sent  to  Scotland.  He  hoped  that  the  next  cargo  might 
be  carried  off  by  Manchester  traders. 
128 
JOURNAL  OF  HORTICULTURE  AND  COTTAGE  GARDENER. 
August  7,  1902. 
