A  ml™;  iP8?3RM }  Obituary.  239 
(Sbitorial  Department 
An  Explosion  of  a  Mixture  of  Chlorate  of  Potassium  and  Tannin, 
we  are  informed,  occurred  again  in  this  city  on  the  sixth  of  April  last,  and  the 
dispenser  was  severely  injured  thereby  in  the  face  and  on  the  hands.  On  page 
470  of  the  American  Journal  of  Pharmacy  for  18€9,  a  similar  case  is  recorded, 
and  others  have  been  noticed  by  medical,  pharmaceutical  and  chemical  journals 
of  this  country  and  elsewhere. 
The  explosive  nature  of  mixtures  of  chlorate  of  potassium  with  combustible 
and  oxidizable  materials  is  well  known  to  chemists,  and  chemical  works  usually 
draw  attention  to  the  danger  attending  the  mixing  of  such  articles  in  a  dry 
state  in  a  mortar  or  with  pressure.  Chemical  students  are  familiar  with  the 
lecture  experiment  of  producing  detonations  by  triturating  the  chlorate  with 
some  sulphur;  such  detonations  unaccompanied  by  danger,  are  liable  to  occur 
even  on  rubbing,  with  some  pressure,  chlorate  of  potassium  in  a  dusty  mortar. 
The  experiment,  however,  becomes  at  once  dangerous,  as  soon  as  a  sufficient 
quantity  of  a  combustible  article  has  been  incorporated  with  the  powdered 
chlorate,  and  the  explosiveness  of  such  mixtures  increases  with  the  combusti- 
bility of  their  ingredients. 
The  blasting  and  so  called  white  gun-powders  which  were  recommended  some 
twenty  years  ago,  are  such  mixtures.  The  former  contain  red  sulphuret  of  arsenic 
or  ferrocyanide  of  potassium,  or  both,  and  their  danger  was  made  manifest  by 
an  accident  which  happened  to  the  inventor  and  patentee,  Mr.  Callow,  who 
was  rendered  a  cripple  for  life.  Such  explosions  are  not  only  liable  to  take 
place  by  rubbing  or  by  a  blow,  but  also  on  the  addition  of  acids  sufficiently  con- 
centrated to  decompose  a  portion  of  the  chlorate  and  locally  heat  the  mixture. 
Strong  sulphuric  acid  is  especially  dangerous  from  the  last  named  causes. 
Whenever  chlorate  of  potassium  is  prescribed  in  the  form  of  powder  mixed 
with  any  organic  or  with  an  oxidizable  inorganic  compound,  the  only  safe  way 
to  dispense  such  a  prescription  is  to  triturate  the  materials  separately  until 
they  are  reduced  to  a  fine  powder,  and  then  mix  the  powders  intimately  upon 
paper  without  friction.  In  preparing  gargles  and  other  liquid  medicines  con- 
taining such  ingredients,  the  latter  should  never  be  mixed  in  a  mortar  until 
after  a  sufficient  quantity  of  water  has  been  added. 
But  even  though  such  dry  mixtures  may  be  prepared  by  the  pharmacist  with- 
out danger  to  himself,  we  question  whether  the  physician  is  justified  to  pre- 
scribe them,  considering  the  danger  to  which  he  exposes  his  patient.  Several 
years  ago,  we  remember  that  such  a  mixture  exploded,  from  some  cause  or  other 
in  the  house  of  the  patient,  happily,  however,  without  doing  any  injury,  except 
setting  fire  to  a  few  contiguous  articles. 
OBITUARY. 
John  Torrey,  M.  D.,  LL.  D.,  was  born  in  New  York  in  the  year  1798,  and 
died  there  March  2d,  aged  75  years.  He  received  his  degree  of  M.  D.  at  the 
College  of  Physicians  and  Surgeons  of  New  York,  and  served  from  1827  to 
1854  as  Professor  of  Chemistry  and  Botany  in  the  same  College,  after  having 
previously  held  for  three  years  the  position  of  Professor  of  Chemistry  in  the 
military  academy  at  West  Point.  Since  1853  to  the  time  of  his  death  he  was 
the  Chief  Assayer  in  the  United  States  Assay  Office  in  New  York. 
Dr  Torrey  was  an  indefatigable  laborer  and  attained  more  than  ordinary 
success  in  various  branches  of  science  ;  but  his  most  important  labors  were  in 
the  field  of  botany.  As  early  as  1817  he  published  a  catalogue  of  the  plants 
growing  within  30  miles  of  New  York,  subsequently  a  "  Flora  of  the  Northern 
United  States,"  and  the  botanical  part  of  the  natural  history  survey  of  the 
State  of  New  York.    In  connection  with  his  former  pupil,  Professor  Asa  Gray,, 
