'^^May^iss?™^  }   Analytical  Researches  and  Investigations.  225 
the  bite  of  a  venomous  serpent,  and  the  substance  consists  principally 
of  an  alkaloid  of  the  nature  of  the  cadaver  poisons  or  ptomaines,  with 
which  it  agrees  in  its  chemical  reactions.  This  discovery,  as  Acart  has 
remarked  in  a  notice  on  the  subject,  may  modify  very  much  the  ques- 
tion of  virulent  diseases ;  for  that  which  in  the  one  case  is  the  result 
of  the  infiltration  of  bacteria  may  be  in  the  other  a  simple  substitu- 
tion of  chemical  compounds.  In  any  case  it  is  certain  that  a  virus  is 
not  here  in  question ;  for  under  the  influence  of  elevated  temperatures 
the  virus  is  destroyed,  while  in  submitting  this  salivary  alkaloid  to  a 
temperature  above  100°C.  its  toxic  property  was  not  diminished.  In 
order  to  give  greater  weight  to  the  facts  which  he  has  submitted, 
Gautier  has  studied  the  comparative  action  of  the  venom  of  one  of  the 
most  formidable  serpents  of  India,  the  najans  tripudians,  or  better 
known  as  the  cobra.  This  venom  when  injected  in  the  dose  of  one 
milligram,  dissolved  in  a  quarter  of  a  cubic  centimeter  of  water,  under 
the  skin  of  a.  little  bird,  such  as  a  chaffinch  or  sparrow,  produced 
death  in  from  five  to  twelve  minutes.  There  was  to  be  observed  tor- 
por, coma,  then  a  period  of  excitement  with  convulsive  movements 
and  tetanic  contractions.  76 id,  Jan.,  1882,  pp.  12,  22;  from  La 
Nature. 
Preparation  of  Nitroglycerin. — Boutmy  and  Foucher  have  recently 
been  awarded  by  the  French  Academy  of  Sciences  the  prize  of  2,500 
francs  for  their  new  and  safe  method  of  the  preparation  of  nitro- 
glycerin. The  process,  consists  in  combining  the  glycerin  with  the 
sulphuric  acid  so  as  to  form  the  glycerin-sulphuric  acid,  and  decom- 
posing the  latter,  slowly,  by  means  of  nitric  acid.  Two  solutions  are 
thus  prepared  :  the  glycerin-sulphuric  acid  and  the  sulpho-nitric  acid, 
the  latter  being  formed  by  the  mixture  of  equal  parts  of  sulphuric  and 
nitric  acids.  These  mixtures  give  rise  to  the  emission  of  a  large 
amount  of  heat,  which  necessitates  the  employment  of  refrigerating 
mixtures.  In  finally  mixing  these  acids  in  convenient  proportions,  a 
reaction  is  produced  which  continues  about  20  minutes.  The  nitro- 
glycerin is  deposited  at  the  bottom  of  the  vessel,  and  may  be  readily 
collected  and  washed.  According  to  the  old  process,  the  reaction  was 
rapidly  accomplished,  and  a  portion  of  the  nitroglycerin  arose  to  the 
surface,  which  rendered  the  operation  of  washing  difficult. — Ibid.^ 
March,  1882,  p.  52. 
Estimation  of  Ergot  in  Bread  and  Flour.  By  Dr.  Pohl. — The 
autlior  communicates  the  following  ready  method  for  the  quantitative 
