Am'ocu''iSiai'm'}    British  Pharmaceutical  Conference.  543 
The  Alkaloid  of  Tea. — In  this  paper  Mr.  Allen  stated  that  theine  could  be 
dried  without  loss  of  weight  at  joo®  C,  and  that  it  undergoes  decomposition 
when  boiled  with  lime  water.  He  recommended  that  in  the  analytical  deter- 
mination of  theine,  tea  should  be  first  extracted  with  water,  and  that  after 
titrating  the  extract  with  lime  or  magnesia,  the  theine  should  be  dissolved  out 
of  the  dried  mixture  with  alcohol.  In  the  discussion  of  this  paper  it  was 
remarked  that  the  points  which  were  beyond  dispute  had  already  been  made 
known,  and  that  in  several  respects  the  statements  made  were  at  least  ques- 
tionable. 
Chloroform. — Mr.  D.  Brown  discussed  tests  for  the  purity  of  chloroform, 
and  gives  exhaustive  tables  to  show  the  relative  value  of  samples  of  Scotch, 
English  and  German  origin.  His  results  show  that  it  is  possible  to  select 
chloroform  of  a  very  high  degree  of  purity,  whilst,  at  the  same  time,  it  would 
appear  that  the  commercial  article  is  by  no  means  uniform  in  quality. 
Aloes. — Mr.  E.  M.  Holmes  has  endeavored  to  account  for  the  differences  in 
character  and  odor  that  distinguish  Curacao  aloes  from  the  ordinary  Barbadoes 
variety.  Both  are  affirmed  to  be  the  produce  of  Aloe  vulgaris  (lam.),  which 
was  introduced  into  the  West  Indies  about  the  beginning  of  the  sixteenth  cen- 
tury. Mr.  Holmes  attempted  to  solve  this  problem  three  years  ago,  when  he 
proved  that  the  former  kind  is  really  obtained  from  Aloe  chinensis  (Baker), 
and  the  conclusion  he  arrived  at  was  that  the  aloes  of  Curacao  was  probably 
modified  to  some  extent  by  an  admixture  of  the  juice  from  the  leaves  of  Aloe 
spicata  and  A.  Succotrina.  This  has  been  disputed  by  Senor  S.  C.  Henriquez, 
a  manufacturer  of  aloes  at  Curacao,  who  sent  specimens  of  his  preparations 
to  the  Pharmaceutical  Society's  Museum  in  March  of  this  year,  together  with 
some  interesting  information  concerning  the  process  of  manufacture.  These 
notes  are  quoted  in  detail  in  Mr.  Holmes'  paper,  together  with  descriptions  of 
the  various  methods  adopted.  It  would  appear  that  the  length  of  time  that 
has  elapsed  since  the  collection  of  the  juice  is  an  important  factor  in  determin- 
ing the  characteristics  of  the  finished  product.  Experiments  conducted  by 
Mr.  Holmes,  with  the  assistance  of  Mr.  H.  D.  Fuge,  point  to  the  fact  that  the 
sooner  the  juice  is  dealt  with  afcer  collection  the  larger  is  the  proportion  of 
soluble  matter  that  can  be  extracted  from  the  dried  aloes  by  boiling  water. 
The  fact  is  noted  also  that  Curacao  aloes  may  differ  considerably  in  appear- 
ance, being  either  dull,  like  Barbadoes,  or  vitreous,  like  Cape  aloes.  It  yet 
remains  to  be  shown  whether  the  Barbadoes  variety  has  the  same  origin  as 
Curacao  aloes,  and  to  what  the  difference  in  odor  is  due. 
Vortmanri's  Test  for  Hydrocyanic  Acid. — Mr.  H.  Bowden  thinks  that  this  test 
has  not  attracted  sufficient  attention.  It  consists  in  adding  to  the  suspected 
liquid  a  few  drops  of  potassium  nitrite  solution  and  three  drops  of  ferric  chloride 
solution.  The  brown  precipitate  produced  is  dissolved  in  dilute  sulpburic 
acid,  the  mixture  boiled,  then  cooled,  and  ammonia  added  to  precipitate  the 
iron.  After  removal  of  the  precipitate,  dilute  freshly-prepared  ammonium 
sulphide  solution  is  added  to  the  filtrate,  when  a  violet  coloration  is  produced 
which  changes  in  turn  to  blue,  green,  and  again  violet.  Mr.  Bowden  has 
applied  the  test  for  the  acid  with  great  success,  and  describes  a  number  of  his 
experiments  in  detail.  When  cyanides  are  in  question  he  prefers  to  liberate 
the  acid  before  testing.    He  considers  that  the  extreme  delicacy  of  the  test, 
