'^'"May'iSr"'}     Minutes  of  the  Pharmaceutical  Meeting.  277 
Action  of  the  Protected  Light. — A  number  of  fresh  and  uninjured  plants 
were  placed  in  the  greenhouse,  and  in  addition  sowings  of  barley,  oats,  peas, 
maize,  beans,  which  had  just  appeared  above  the  ground.  All  the  seedlings 
exposed  exclusively  to  the  electric  light  perished  sooner  or  later,  and  the 
leaves  of  some  of  them  were  blackened  as  with  the  naked  light.  The  mature 
plants,  on  the  other  hand,  continued  to  vegetate,  but  in  no  case,  save  a  plant 
of  barley,  were  flowers  and  seeds  produced,  the  vegetation  being  purely 
foliaceous.  The  barley  grains  were  normal,  and  germinated  (»n  beingsown. 
The  electric  light  employed  was  clearly  insufficient  by  itself  to  determine 
the  assimilation  of  any  considerable  quantity  of  material ;  direct  experi- 
ments also  proved  that  it  is  not  more  powerful  in  exciting  transpiration  of 
water,  a  leaf  exposed  to  it  giving  off  in  an  hour  only  about  one-flftieth  of 
the  quantity  of  water  evaporated  under  similar  circumstances  in  sunlight. 
As  the  evaporation  of  water  by  the  leaves  is  one  of  the  chief  agencies  in 
causing  the  migration  of  material  necessary  for  the  maturation  of  seed,  the 
failure  of  the  plants  to  produce  flowers  and  seeds  receives  its;  explanation. 
It  is  known  that  yellow  and  red  rays  are  most  powerful  in  causing  transpi- 
ration, whilst  the  electric  light  is  particularly  rich  in  blue  and  violet  rays. 
The  author  considers  the  electric  light  employed  as  too  feeble  to  allow  of  any 
■conclusion  as  to  the  necessity  of  a  nocturnal  rest  to  plants.  It  was,  however, 
-evident  that  the  electric  illumination  during  the  night  was  advantageous  to 
those  plants  which  passed  the  day  in  the  rather  feeble  diffused  daylight  of 
the  palace.  In  a  third  series  of  experiments,  the  intensity  of  the  electric 
light  was  practically  augmented  by  placing  the  plants  near  the  lamp.  The 
-experiment  was  again  fatal  to  young  seedlings  receiving  the  electric  light 
•exclusively,  but  many  of  the  hardier  and  more  mature  plants  survived, 
although  the  leaves  of  some  were  blackened  by  their  too  great  proximity  to 
the  light;  and  again  the  nocturnal  electric  illumination  was  decidedly 
favorable  to  the  plants  which  passed  the  day  in  the  light  of  the  palace.  The 
author  sums  up  his  conclusions  thus: — 
1.  The  electric  arc-light  emits  radiations  which  are  injurious  to  vegetation. 
2.  Most  of  these  radiations  are  arrested  by  colorless  glass. 
3.  The  electric  light  emits  radiations  powerful  enough  to  maintain  mature 
plants  in  vegetation  for  two  months  and  a  half. 
4.  The  beneficial  radiations  are  not  sufficiently  powerful  to  cause  the 
:growth  of  germinating  seeds,  or  to  allow  of  the  maturation  of  fruit  in  older 
plants.— »/owr.  Chem.  Soc,  1883,  105.    Ann.  Agronom.,  vii,  551-575. 
f 
MINUTES  OF  THE  PHARMACEUTICAL  MEETING. 
Philadelphia,  April  16,  1883. 
In  the  absence  of  the  president,  Mr.  Alonzo  Bobbins  was  called  to  the 
<}hair. 
The  minutes  of  the  last  meeting  were  read  and  approved. 
The  following  donations  to  the  library  and  museum  were  made :  Proceed- 
ings of  the  American  Pharmaceutical  Association  for  the  year  1882,  from  the 
