﻿400 
  

  

  198 
  iiig., 
  dry 
  sodium 
  arsenite 
  1*28 
  mg. 
  These 
  figures 
  show 
  the 
  

   comparative 
  risk 
  incurred 
  when 
  handHng 
  arsenicals 
  in 
  the 
  form 
  in 
  

   w^hich 
  the 
  agriculturist 
  receives 
  them. 
  Lead 
  arsenate 
  is 
  the 
  least 
  

   dangerous, 
  particularly 
  if 
  prepared 
  in 
  the 
  form 
  of 
  paste. 
  Winter 
  

   insecticides 
  (sodium 
  arsenite) 
  would 
  be 
  about 
  102 
  times 
  as 
  poisonous 
  

   as 
  spring 
  insecticides 
  (lead 
  arsenate), 
  if 
  the 
  winter 
  insecticide 
  (a 
  

   commercial 
  solution) 
  tested 
  by 
  the 
  author 
  may 
  be 
  taken 
  as 
  represen- 
  

   tative 
  and 
  the 
  effect 
  of 
  the 
  poison 
  be 
  the 
  same 
  on 
  man 
  as 
  on 
  rabbits. 
  

   In 
  a 
  supplement 
  to 
  this 
  paper 
  the 
  author 
  reports 
  on 
  an 
  experiment 
  

   he 
  made 
  w^ith 
  a 
  view 
  to 
  establishing 
  whether 
  dangerous 
  traces 
  of 
  

   poison 
  are 
  present 
  on 
  the 
  edible 
  portions 
  of 
  vegetables 
  sprayed 
  with 
  

   arsenicals. 
  The 
  tests 
  were 
  made 
  with 
  specially 
  sprayed 
  asparagus. 
  

   A 
  bundle 
  of 
  35 
  heads, 
  sufficient 
  for 
  several 
  people, 
  only 
  contained 
  

   1*1 
  milligramme 
  of 
  arsenic. 
  It 
  should 
  be 
  noted 
  that 
  these 
  plants 
  were 
  

   sprayed 
  much 
  more 
  heavily 
  than 
  in 
  normal 
  practice. 
  It 
  is 
  pointed 
  

   out 
  that 
  asparagus 
  and 
  most 
  other 
  vegetables 
  contain 
  some 
  thousandths 
  

   of 
  a 
  milligramme 
  of 
  arsenic 
  and 
  the 
  few 
  hundredths 
  of 
  a 
  milligramme 
  

   accidentally 
  left 
  on 
  them 
  by 
  spray 
  treatment 
  on 
  adjacent 
  vines 
  can 
  

   do 
  no 
  harm, 
  as 
  a 
  dose 
  about 
  10,000 
  times 
  as 
  large 
  was 
  necessary 
  to 
  

   cause 
  appreciable 
  ill 
  effects 
  in 
  rabbits. 
  

  

  PiCARD 
  (F.) 
  Considerations 
  sur 
  I'emploi 
  des 
  arsenicaux 
  dans 
  la 
  region 
  

   m6ridionale. 
  [The 
  employment 
  of 
  arsenicals 
  in 
  the 
  South 
  of 
  

   France.] 
  — 
  Ann. 
  du 
  Service 
  des 
  Epiphyties 
  (1912), 
  Paris, 
  1913, 
  

   pp. 
  76-79. 
  [Eeceived 
  18th 
  Feb. 
  1914.] 
  

  

  Spring 
  treatment 
  with 
  lead 
  arsenate 
  especially 
  aims 
  at 
  combating 
  

   Clysia 
  and 
  Polychrosis. 
  Lead 
  arsenate 
  is 
  also 
  the 
  onl}" 
  insecticide 
  at 
  

   present 
  used 
  against 
  two 
  beetles 
  which 
  are 
  abundant 
  in 
  the 
  South 
  

   and 
  recurrent 
  every 
  year, 
  Haltica 
  and 
  Rhynchites. 
  The 
  former 
  is 
  by 
  

   far 
  the 
  more 
  dangerous 
  and 
  lead 
  arsenate 
  has 
  alone 
  made 
  control 
  of 
  

   it 
  possible. 
  In 
  the 
  case 
  of 
  Rhynchites 
  also 
  it 
  does 
  not 
  seem 
  feasible 
  

   to 
  replace 
  lead 
  arsenate 
  by 
  another 
  insecticide. 
  It 
  is 
  not 
  quite 
  suc- 
  

   cessful 
  with 
  Clysia, 
  but 
  neither 
  are 
  other 
  insecticides. 
  Winter 
  treat- 
  

   ment 
  is 
  practised 
  with 
  sodium 
  arsenite, 
  either 
  by 
  itself 
  or 
  compounded 
  

   with 
  other 
  substances 
  of 
  little 
  insecticidal 
  value, 
  but 
  in 
  the 
  author's 
  

   opinion, 
  it 
  is 
  not 
  an 
  efficacious 
  remedy 
  and 
  had 
  better 
  be 
  abandoned, 
  

   particularly 
  as 
  cases 
  of 
  poisoning 
  through 
  its 
  use 
  are 
  not 
  unknow^n. 
  

   No 
  authentic 
  case 
  of 
  poisoning 
  has 
  been 
  recorded 
  in 
  the 
  use 
  of 
  lead 
  

   arsenate. 
  

  

  PiCARD 
  (F.). 
  La 
  teigne 
  des 
  pommes 
  de 
  terre. 
  {Phthoriniaea 
  opercu- 
  

   lella). 
  [The 
  potato 
  tuber 
  moth. 
  ]^^nn. 
  du 
  Service 
  des 
  Epiphyties 
  

   (1912), 
  Paris, 
  1913, 
  pp. 
  106-176, 
  23 
  figs. 
  [Received 
  18th 
  Feb. 
  

   1914.] 
  

  

  The 
  author 
  deals 
  very 
  fully 
  with 
  the 
  biology 
  of 
  Phthorimaea 
  oper- 
  

   cidella, 
  Z. 
  {Lita 
  solanella, 
  Rag.) 
  on 
  the 
  potato, 
  and 
  points 
  out 
  that 
  

   when 
  the 
  larvae 
  are 
  full 
  fed, 
  they 
  generally 
  emerge 
  from 
  the 
  tuber 
  

   and 
  try 
  to 
  ascend 
  as 
  far 
  as 
  possible 
  in 
  order 
  to 
  spin 
  their 
  cocoons. 
  

   The 
  whole 
  development 
  progresses 
  more 
  quickly 
  as 
  w^armth 
  increases, 
  

   but 
  the 
  lower 
  limit 
  of 
  temperature 
  at 
  which 
  growth 
  is 
  interrupted, 
  

   was 
  not 
  exactly 
  ascertained 
  owing 
  to 
  lack 
  of 
  equipment 
  ; 
  apparently 
  

   neither 
  hatching 
  nor 
  larval 
  growth 
  was 
  observable 
  under 
  50° 
  Fahr. 
  

  

  