414 
North  American  Coniferce. 
/Am.  Jour.  Pbarm. 
I      August,  1896. 
On  distillation  with  water  or  steam,  the  resin  of  spruce  yields  a 
volatile  oil,  which  boils  at  1600  and  appears  to  be  composed  almost 
entirely  of  terpene,  C10H16.  The  residual  resin,  after  removal  of  vol- 
atile oil,  was  found  by  Menges  to  be  soluble  in  alcohol,  methyl  alco- 
hol, ether  and  chloroform,  sparingly  soluble  in  benzol  and  insoluble 
in  petroleum  ether ;  it  did  not  afford  crystals  of  abietic  acid  when 
digested  with  alcohol  of  0  890  specific  gravity,  thus  differing  from 
colophony ;  and  when  treated  with  dilute  nitric  acid  it  yielded  picric 
acid,  whereby  it  further  differed  from  colophony. 
ECONOMICS. 
The  wood  of  this  tree  is  rather  compact,  straight-grained,  soft 
and  light,  usually  reddish  in  color,  and,  though  not  very  strong,  is, 
by  reason  of  its  lightness  and  elasticity,  much  used  in  construction. 
It  is  largely  used  for  spars,  the  knees  of  vessels,  the  rafters  of 
houses,  railway  ties,  and  for  manufacture  of  lumber.  The  twigs 
are  also  employed  for  brewing  spruce  beer,  which,  in  the  north- 
eastern part  of  the  United  States  and  in  Canada,  is  regarded  as  a 
wholesome  drink. 
PICEA  PUNGENS,  ENGELMANN. 
COLORADO  BLUE  SPRUCE. 
DISTRIBUTION  AND  GENERAL  CHARACTERS. 
The  blue  spruce  is  western  in  its  range,  being  found  in  the  moun- 
tains of  Colorado,  Wyoming  and  Utah.  In  favorable  situations  it 
becomes  a  large  tree,  attaining  a  height  of  150  feet,  and  a  diam- 
eter of  3  feet.  It  does  not,  like  the  two  species  just  considered, 
form  large  forests,  but  is  rather  rare  or  of  local  occurrence.  The 
species  has  a  thick,  smooth,  gray  bark,  which,  on  old  stems,  is 
fissured.  Its  branches  are  horizontally  spreading,  and  its  branchlets 
are  smooth  and  glossy.  Its  cones  are  solitary  or  clustered,  cylindri- 
cal, drooping,  light  brown  in  color,  and  2]/2  to  5  inches  long.  The 
scales  are  oval,  more  or  less  undulate,  margined  and  retuse. 
MICROSCOPICAL  STRUCTURE. 
A  cross-section  of  the  stem  of  two  years'  growth  showed  the 
following  structure  :  an  epidermis  of  thick-walled  cells,  supported  by 
two  or  three  layers  of  thick-walled  hypodermal  cells.  Beneath  this 
was  a  thin-walled  parenchyma,  similar  to  that  described  in  the  other 
two  species.    Bounding  this  on  the  interior  was  the  periderm  layer, 
