Am.  Jour.  Pharm.  ) 
February,  1914.  J 
The  Starch  Grain. 
81 
These  are  only  two>  of  many  fundamental  results  contained  in  this 
wonderful  memoir.  Van't  HofT  extended  the  gas  laws  to  solutions. 
Perrin  has  now  proved  them  to  be  valid  for  systems  in  which  the 
moving  particles  are  visible  realities.  Let  us  end  by  quoting  one  of 
the  sentences  of  his  conclusion : 
"  ha  decouverte  de  telles  relations  marque  le  point  ou  s'eUve, 
dans  notre  conscience  scientiUque,  la  realite  moleculaire  sousjacente." 
THE  INFLUENCE  OF  HEAT  AND  CHEMICALS  ON  THE 
STARCH  GRAIN.1 
By  Henry  Kraemer. 
In  presenting  some  of  the  most  recent  observations  on  the  starch 
grain,  it  may  be  well  to  consider  for  a  moment  the  nature  and 
origin  of  starch.  In  a  way  starch  is  one  of  the  most  remarkable 
substances  produced  by  the  plant.  It  is  the  first  visible  product 
formed  by  the  chloroplastid,  or  chlorophyll  bodies,  from  the  inor- 
ganic substances,  carbon  dioxide  and  water.  Inasmuch  as  sunlight 
seems  to  be  necessary  to  bring  about  this  transformation  the  process 
is  looked  upon  as  one  which  involves  the  converting  of  the  sun's 
energy  into  vital  energy. 
The  substance  thus  formed  by  the  chloroplastid  through  the 
influence  of  sunlight,  in  the  leaves  and  other  green  parts  of  plants, 
is  known  as  "  assimilation  starch,"  and  serves  subsequently  not 
only  as  a  food  for  the  plant  itself  but  is  also  the  source  of  the 
energy  of  the  animal  world.  Assimilation  starch  is  not  stored  in 
the  cells  where  it  is  manufactured,  but  each  night  through  the 
influence  of  the  plant  ferments  the  starch  formed  during  the  day 
is  converted  into  a  soluble  form,  and  transported  to  various  other 
parts  of  the  plant.  In  some  cases  this  soluble  starch  is  tem- 
porarily stored  in  the  cells  of  the  pith,  medullary  rays,  or  bark, 
and  has  received  the  name  of  "  depot  starch."  While  some  of 
the  soluble  carbohydrate  is  converted  into  fixed  oils  and  other 
substances,  a  considerable  portion  of  it  is  carried  to  some  reserve 
organ,  as  a  root,  tuber,  rhizome,  or  seed,  and  under  the  influ- 
ence of  a  plastid  similar  to  the  chloroplastid,  converted  into  a 
stable  form,  known  as  reserve  starch. 
1  Reprinted  from  Original  Communications,  Eighth  International  Con- 
gress of  Applied  Chemistry.    Vol.  XVII — Page  31. 
