52  Camphor — Natural  and  Synthetic. 
Properties  and  Uses. 
Camphor  is  a  colorless,  crystalline  substance  melting  at  1750  C. 
It  is  volatile  at  ordinary  temperature,  and  its  characteristic  odor  is 
said  to  be  detectable  at  a  dilution  of  0.000005  gramme  camphor  in  1 
litre  of  air.  One  part  of  camphor  requires  about  1000  parts  of  cold 
water  for  solution.   It  dissolves  in  organic  solvents  with  ease. 
Japanese  camphor  has  a  strongly  dextrorotatory  action  on  the 
plane  of  polarized  light,  =  44.20  in  alcoholic  solution.  The  laevo- 
rotatory  camphor  occurs  in  the  oil  of  Matricaria  parthenum  and  is 
known  as  Matricaria  camphor.  It  is  identical  with  Japan  camphor, 
except  for  its  opposite  rotatory  power. 
Camphor  finds  application  chiefly  in  three  directions  : 
1.  In  Pharmacy. — Camphor  is  used  in  more  than  thirty  different 
forms.  It  is  antispasmodic,  a  stimulant,  cardiac  and  local  anodyne, 
and  is  used  in  fevers,  dysmenorrhea,  colic,  etc.  Camphor  is  also 
used  as  a  disinfectant. 
2.  In  Explosives. — Camphor  is  said  to  exercise  a  preservative 
action  on  blasting  gelatine,  but  only  a  small  quantity  is  used  in  the 
manufacture  of  explosives. 
3.  In  Celluloid. — Celluloid  was  invented  in  1869  Dv  Hyatt  in 
America,  while  Daniel  Spill  worked  at  the  same  time  in  England. 
The  process  of  manufacture,  expressed  in  a  few  words,  consists  of 
the  incorporation  of  camphor  with  nitrocellulose  and  a  suitable 
solvent  such  as  acetone. 
The  celluloid  industry  consumes  about  three-fourths  of  the  total 
camphor  produced,  a  fact  which  will  be  readily  understood  when  one 
thinks  of  the  enormous  number  of  articles  now  made  of  celluloid. 
Chemical  Constitution  of  Camphor. 
This  has  been  a  subject  of  such  importance  that  it  is  desirable  to 
pass  in  review  the  steps  leading  up  to  the  establishment  of  the  chem- 
ical structure  of  camphor. 
Camphor  belongs  to  the  important  class  of  compounds  called 
terpenes,  the  parent  substances  of  this  group  being  unsaturated  hy- 
drocarbons possessing  the  empirical  formula  C5H8.  The  terpenes 
fall  into  four  classes:  (1)  Hemiterpenes  (C5H8),  (2)  Terpenes 
(C10H16),  (3)  Sesquiterpenes  (C15H24),  (4)  Polyterpenes  (C5H8)n. 
Camphor  is  a  derivative  of  the  second  of  the  above  classes,  and 
possesses  the  formula  C10H16O.    It  is  a  saturated  compound  and 
