Am.  Jour.  Pharni. ) 
December,  1915.  f 
Progress  in  Applied  Science. 
569 
servedly  for  general  use.  Where  arsenate  of  calcium  was  combined 
with  lime-sulphur  it  was,  as  a  rule,  even  more  effective  as  a  poisoning 
agent  than  when  used  alone,  and  did  not  lessen  the  value  of  the  latter 
as  a  fungicide.  When  these  compounds  are  combined,  the  amount 
of  foliage  consumed  by  -the  larvae  is  less  than  where  the  arsenate 
of  calcium  is  used  alone.  In  tests  in  1914  a  commercial  arsenate  of 
calcium  (paste),  arsenic  oxide  18.82  per  cent.,  with  lime-sulphur 
solution,  gave  very  excellent  control  of  the  codling  moth  in  com- 
parison with  arsenate  of  lead  and  with  unsprayed  plats.  Where 
arsenate  of  calcium  was  used,  98.79  per  cent,  of  the  apples  were 
sound;  arsenate  of  lead  showed  99.44  per  cent,  of  sound  apples; 
while  in  the  unsprayed  test  plats  only  58.71  per  cent,  of  the  apples 
were  free  from  damage. 
The  following  will  be  found  to  be  a  convenient  way  of  making 
home-made  arsenate  of  calcium: 
Stone  lime  (90  per  cent.  CaO)   55  pounds 
Sodium  arsenate,  fused  (dry  powdered)  65%  As205   100  pounds 
Water    26  gallons 
Place  the  stone  lime  in  a  wooden  container  and  add  a  small 
amount  of  water,  just  enough  to  start  slaking.  When  slaking  is 
well  under  way,  pour  in  the  sodium  arsenate,  which  should  first 
have  been  dissolved  in  hot  water.  Keep  stirring  until  the  lime  has 
thoroughly  slaked.  Sufficient  water  should  be  added  from  time  to 
time  to  prevent  burning. 
The  resulting  arsenate  of  calcium  should  contain  about  18  per 
cent,  of  arsenic  oxide.  In  making  this  compound  it  will,  of  course, 
be  necessary  to  know  approximately  the  calcium  oxide  and  arsenic 
oxide  content  of  the  materials  employed  and  to  vary  the  formula 
accordingly.  The  by-product  is  largely  sodium  hydroxide,  which 
should  be  decanted  if  the  insecticide  is  to  be  used  on  tender  foliage. 
Effects  of  Selection  on  Alkaloids  in  Belladonna. 
Under  the  title  "  Some  Effects  on  the  Production  of  Alkaloids 
in  Belladonna,"  the  United  States  Department  of  Agriculture,  in 
Bulletin  306,  gives  the  results  of  a  series  of  tests  on  controlling 
pollination  of  first-  and  second-generation  plants,  with  especial  at- 
tention to  cross-pollination  and  close-pollination.  Following  are  the 
conclusions  reached  in  the  bulletin : 
It  having  been  established  in  the  previous  investigation  that  a 
