580  Vesicating  Beetles  from  South  Africa.  {AmN™.%h7arm" 
transverse  sinuous  bands,  and  having  a  very  conspicuous  reniform  or 
semilunar  spot  at  the  base  of  each  wing  case,  also  another  lenticular 
spot  on  the  under  costal  basilar  margin,  which  is  not  visible  unless  the 
beetle  is  turned  over  on  its  back.  The  color  of  all  these  markings 
varies  in  different  individuals,  from  a  dull  ochraceous-yellow  to  a 
bright  lemon-chrome.  The  tarsi  of  the  first  two  pairs  of  legs  are  five 
jointed,  those  of  the  last  pair  have  four  joints. 
The  next  step  was  to  determine  if  either  species  were  active  vesi- 
cants, and  if  so,  the  proportion  in  which  the  blistering  principle  ex- 
isted. As  the  quantity  of  Mylabris  bifasciata  available  was  so  much 
greater  than  that  of  M.  lunata,  this  species  was  operated  on  first. 
Note  by  the  Editor. — By  exhausting  the  beetles  with  acetic 
ether,  washing  the  extract  with  carbon  bisulphide  and  with  a  little 
alcohol,  then  recrystallizing  from  chlorofrom,  the  author  obtained  1*02 
per  cent,  of  cantharidin.  In  another  experiment,  omitting  treatment 
with  chloroform,  the  yield  was  1*09  percent.  A  sample  of  Cantharis 
vesicatoria  yielded  0*42  per  cent.  ;  but  Mylabris  lunata  only  0*296 
per  cent. 
Mr.  Braithwaite  states  that  the  highest  record  of  cantharidin  he 
could  find  was  from  Lytta  aspersa.  R.  Wolff  reported  (Arch.  Phar.y 
Jan.,  1877)  the  yield  to  be  0'855  per  cent.  We  obtained  (Proc.  Am. 
Phar.  Asso.,  1872,  p.  258)  from  Mylabris  cichorii  1*016  per  cent., 
and  L.  Fahnestock  (Am.  Jour.  Phar.,  1879,  p.  297),  from  the  same 
lot  of  these  beetles  nearly  1*25  per  cent.,  the  increased  yield  being 
probably  due  to  the  presence  of  less  moisture,  and  from  Cantharis 
vittata,  1*03  per  cenk  of  cantharidin. 
Preservation  of  Leeches. — J.  T.  writes  to  the  Chemist  and  Druggist, 
August  6, 1887  :  "  I  never  give  leeches  any  meat  or  worms  ;  they  are  kept  in 
an  earthenware  vase,  which  has  been  in  use  about  fifty  years,  with  glass  cover 
and  perforated  zinc  rim ;  in  the  bottom  are  a  few  pebbles,  and  part  of  an 
earthenware  drainer,  through  the  holes  of  which  the  leeches  crawl  when  they 
require  a  little  help  to  cast  their  skins.  The  ordinary  tap-water  (off  the 
limestone)  with  which  they  are  supplied  is  changed  three  times  a  week  in 
summer,  and  once  or  twice  a  week  in  winter.  Loss  or  complaints  are 
very  rare,  sometimes  not  once  in  six  months.  I  always  dry  leeches  before 
selling,  for  two  reasons;  (1)  because  they  bite  more  readily,  and  (2)  because 
the  glue  of  the  box  is  often  moistened  when  they  are  sent  a  distance.  I 
should  think  the  weeds,  earth,  etc.,  which  some  advocate,  would  make  it 
rather  difficult  to  find  half  a  dozen  or  so. 
