"^"M^rissr"""}      ^^^^  Microscope — Hints  to  Beginners.  255 
require  a  little  patience,  without  a  good  supi^ly  of  which  no  one  can  be  a 
successful  microscopist.  After  teasing  it  out  as  much  as  possible,  select 
the  thinnest  strands  and  place  them  on  a  slide ;  examine  with  a  pocket 
magnifier,  and  if  you  have  separated  a  spiral  vessel  transfer  it,  by  means 
of  a  bent  needle,  to  another  slide;  place  a  drop  of  water  on  it  and  cover 
with  a  glass  circle,  then  examine  with  a  1-inch  power,  which  will  show 
the  spirals  well.  They  are  rather  delicate  objects,  and  if  much  meddled 
with  will  easily  break.  Double  spirals  can  be  seen  in  thin  shavings  of  the 
yew-tree,  but  require  a  very  high  power  to  show  well.  They  give  great 
strength  and  elasticity  to  the  wood  ;  hence  its  use  in  olden  times  in  the 
manufacture  of  bows. 
Disc-bearing  cells  will  be  found  an  any  coniferous  wood — common  deal 
or  the  ordinary  cedar-wood  of  pencils.  Very  thin  sections  with  the  razor 
will  show  the  cells  without  any  previous  treatment ;  a  very  thin  shaving 
with  a  carpenter's  plane  is  even  better  than  one  made  by  the  razor,  as  the 
plane  makes  the  section  of  a  uniform  thickness,  which  is  apt  not  to  be  the 
case  when  the  razor  is  used. 
Scalariform  vessels  are  easily  found  in  ferns,  a  longitudinal  section  from 
a  tree-fern  giving  a  good  specimen.  By  making  an  oblique  section  near 
the  base  of  the  stalk  of  the  common  hart's-tongue  fern  one  will  find  a  very 
good  example  of  this  kind  of  tissue. 
Plant  hairs  are  so  common  that  a  notice  of  one  or  two  of  them  will  be 
sufficient.  A  favorite  slide  among  microscopists  is  one  showing  the  stel- 
late hairs  of  the  deutzia.  They  are  found  on  the  surface  of  the  leaf,  and 
are  usually  shown  as  an  opaque  object  under  condensed  light ;  by  this  is 
meant  the  shutting  off  of  the  rays  of  light  from  the  reflecting  mirror  with 
the  diaphragm,  and  throwing  on  the  object  a  beam  of  light  obtained  from 
the  side  condensing  lens.  The  column  of  the  monadelphous  stamens  of 
the  common  mallow  have  beautiful  hairs,  which  under  polarized  light  are 
lovely  objects.  They  are  obtained  by  cutting  away  the  staminal  portion 
of  the  flower,  and  placing  it  longitudinally  in  a  slit  made  in  a  small  phial 
cork  ;  with  the  razor  make  a  very  thin  slice,  which  will  most  probably 
adhere  to  the  blade ;  this  must  be  washed  off  into  a  small  saucer,  and  then 
transferred  to  a  glass  slip  for  examination  in  the  usual  way ;  if  a  satisfac- 
tory specimen  has  been  obtained,  it  ought  to  be  placed  in  a  little  spirit  and 
water  in  a  very  small  phial  until  it  is  required  for  mounting.  Nux 
vomica  seeds  are  covered  with  very  fine  hairs,  which  give  them  that 
silky  appearance  and  feeling  between  the  fingers;  they  likewise  make 
good  objects  for  mounting,  as  they  show  well  when  viewed  by  polarized 
light. 
In  order  to  observe  that  very  interesting  sight,  the  gyration  of  the  cell 
contents,  several  water  plants,  such  as  chara,  nitella,  and  anacharis,  may 
be  chosen  to  advantage.  Anacharis  is  easily  obtained  from  any  canal  or 
river;  it  is  commonly  known  as  water  thyme,  or  the  new  river  weed,  and 
is  an  exceedingly  quick  grower,  as  is  shown  by  the  fact  that  though  only 
introduced  about  fifty  years  ago,  yet  it  has  overrun  Great  Britain  and 
choked  rivers  and  canals  until  it  has  become  a  positive  nuisance.  If  a 
leaf  of  this  j)Iant  be  laid  on  a  slide,  a  drop  of  water  placed  on  it  and  cov- 
ered witli  a  circle,  it  will  show  under  a  1-inch  power  the  circulation  of  the 
