^oVeZerfmTI       Hygienic  Laboratory  Bulletins.  537 
keeping  qualities  of  untreated  sera  and  sera  concentrated  by  the 
Gibson  process. 
"  Diphtheria  antitoxin  to  be  placed  upon  the  market  and  there 
kept  under  unknown  conditions  as  regards  temperature  should  not 
be  labeled  with  a  return  date  longer  than  two  years  and  should 
contain  an  excess  of  at  least  33  per  cent,  to  allow  for  decrease  in 
potency;  in  addition,  when  the  serum  is  sold  in  syringes  with  an 
absorbable  piston,  an  excess  should  be  added  for  this  loss. 
"Dried  diphtheria  antitoxin,  kept  in  the  dark,  at  50  C,  retains 
its  potency  practically  unimpaired  for  at  least  five  and  one-half 
years. 
"  The  lack  of  confidence  in  the  therapeutic  properties  of  old  sera 
is  without  basis,  as  such  sera,  unit  for  unit,  are  as  potent  as  new 
sera. 
"  The  protective  value  of  diphtheria  antitoxin  is  in  exact  accord 
with  its  unit  value  and  is  independent  of  the  volume  of  the  serum 
or  other  properties  in  the  serum." 
The  two  contributions  by  Norman  Roberts  are  also  of  interest  to 
pharmacists  engaged  in  laboratory  work.  The  colorimeter  described 
should  prove  to  be  useful  and  more  economical  in  construction  than 
any  of  the  instruments  of  this  kind  now  available. 
The  gas  generator  in  the  several  forms  described  would  appear  to 
meet  the  requirements  for  which  they  were  designed  and  are  sug- 
gestive of  simple  modifications  that  could  be  adapted  to  the  every- 
day needs  of  any  laboratory. 
Hygienic  Laboratory  Bulletin  No.  65.  Facts  and  Problems  of 
Rabies.  By  A.  M.  Stimson.  Washington,  Government  Print- 
ing Office,  1910,  p.  85,  pi.  V. 
This  bulletin,  while  by  no  means  pharmaceutical  in  nature,  is, 
nevertheless,  of  interest  to  pharmacists  because  of  the  complete  way 
in  which  a  much  dreaded  disease  is  described  and  methods  for  its 
prevention  or  complete  eradication  outlined. 
After  comprehensively  reviewing  the  history,  prevalence,  pathol- 
ogy, and  etiology  of  rabies,  Stimson  discusses  its  prevention  and 
treatment  and  concludes^  in  part,  that :  "  It  is  apparent  that  the 
disease  is  quite  prevalent  in  the  lower  animals  and  not  as  rare  in 
man  as  has  been  supposed.  Exact  information  as  to  its  prevalence 
in  the  United  States  is  not  available  and  its  acquisition  is  necessary. 
