AlAp?iir*i92iarm'  \  Scientific  Abstracts.  285 
the  actual  need.  Antibody  production  is  thus  nothing  more  than 
one  form  of  the  physiologic  regeneration  of  the  blood,  this  regen- 
eration carried  to  excess.  The  antigen  and  the  antibody  unite  in  a 
collodial  combination,  and  this  shuts  off  the  functioning  of  the 
antibody  from  the  blood.  The  organism  responds  to  this  loss  of  the 
antibody  functioning  by  an  extra  secretion  to  produce  more  of  the 
antibody.  Accepting  the  above  three  premises  entails  the  further 
premise  that  the  blood  is  a  secretion,  and  he  presents  an  array  of 
arguments  to  sustain  this  view. — From  Schweizerische  medizinische 
Wochenschift,  Basel,  through  Jour.  Amer.  Med.  Assoc.,  Jan.  29, 
1921. 
Chemical  Constitution  and  Toxicity  to  Wireworms. — 
The  relationship  between  chemical  constitution  and  toxicity  to  wire- 
worms  of  organic  compounds  is  found  to  be  of  a  two-fold  nature. 
The  general  "effect  of  a  group  of  compounds  of  the  same  type  is 
directly  determined  by  the  chemical  constitution  of  the  type.  The 
particular  effects  of  individual  members  of  the  groups  are  limited 
by  their  physical'  properties,  such  as  volatility,  etc.,  which  may  be 
regarded  as  indirect  consequences  of  their  chemical  constitutions. 
The  aromatic  hydrocarbons  and  halides  are  on  the  whole  more  toxic 
than  the  aliphatic  hydrocarbons  and  halides.    The  groups  which 
influence  toxicity  most  when  introduced  into  the  benzene  ring  are, 
in  order  of  importance,  the  methylamido  (most  effective),  dimethy- 
lamido,  hydroxy,  nitro,  amido,  iodine,  bromine,  chlorine,  methyl 
groups  (least  effective).    But  this  order  is  modified  in  presence 
of  another  group;  thus  when  there  is  a  methyl  already  present  in 
the  ring  the  order  becomes  chloride  (side  chain),  amido,  hydroxy, 
chlorine  (ring)  methyl.      Chlorine  and  hydroxy  groups  together 
give  rise  to  highly  poisonous  substances  considerably  more  effective 
than  where  present  separately.    The  association  of  chlorine  and 
nitro  groups  in  chloropicrin  gives  rise  to  one  of  the  most  toxic 
substances  tested.     Methyl  groups  substituted  in  the  amido  group 
of  aniline  increase  toxicity  more  than  if  substituted  in  the  ring. 
Compounds  with  irritating  vapors  usually  have  high  toxic  values. 
In  a  series  of  similar  compounds  decreases  in  vapor  pressure  and 
in  volatility  are  associated  with  an  increased  toxicity.    A  limit  ia 
put  on  toxicity  by  the  decrease  of  vapor  pressure  when  it  sinks 
