Ma^rch  if isn"' }  Mluutes  of  PJi CIV moxieiUical  Meetings.  135 
4th.  To  make  a  definite  quantity  of  any  desired  strength  by  mixing  a  stronger 
and  weaker  alcohol. 
Ansiver  to  ProUem  \st. — Multiply  the  quantity  of  the  alcohol  (either  in  fluid 
ounces  or  in  gallons)  by  its  percentage  strength  (Tralle's  alcoholometer)  and 
divide  by  the  required  per  cent,;  the  quotient  gives  the  quantity  to  which  the 
alcohol  must  be  diluted. 
Ansiver  to  Problem  2d. — Multiply  the  required  amount  by  the  required  per 
cent.,  and  divide  by  the  per  cent,  of  the  given  alcohol  ;  the  quotient  gives  the 
quantity  to  which  the  alcohol  must  be  made  up  by  the  addition  of  water. 
Ansiver  to  Problem  3d. — Subtract  the  percentage  of  the  weaker  alcohol  from 
the  required  per  cent.  ;  the  ditference  indicates  the  quantity  of  the  stronger 
alcohol  to  be  used.  Next,  subtract  the  required  per  cent,  from  that  of  the 
stronger  alcohol;  the  result  indicates  the  quantity  of  the  weaker  alcohol  to  be 
used.  Mix  the  two  results  together  and,  as  the  contraction  will  be  more  or  less, 
add  sufficient  water  to  make  the  mixture  equal  to  the  quantity  of  the  two  liquids 
before  mixing.  For  example,  it  is  desired  to  prepare  an  alcohol  of  60  per  cent, 
by  mixing  an  alcohol  of  90  per  cent,  and  one  of  40  per  cent. 
(  40  =  20  of  the  90  per  cent,  alcohol. 
*^^|  90  =  30     "  40 
Add  water  sufficient  to  make  50  parts. 
Ansv;er  to  Problem  Uh. — Ascertain  the  quantity  of  each  alcohol  to  be  mixed 
(by  Prob.  3d).  The  proportion  which  the  required  amount  bears  to  the  quan- 
tity thus  shown  will  indicate  the  relative  proportion  of  each  alcohol  to  be  used. 
Thus,  if  30  parts  were  required  to  be  made  from  the  two  liquids  given  in  the 
previous  example,  as  30  is  to  3-5ths  of  the  mixture,  then  3-5ths  of  each  alcohol  must 
be  taken,  or  12  parts  of  the  90  per  cent,  alcohol  and  18  parts  of  the  40  per 
cent,  alcohol,  adding  sufficient  water  to  make  30  parts. 
These  rules  comprise  most  cases  which  are  likely  to  occur  in  preparing  solu- 
tions of  alcohol  in  water,  and  are  interesting  problems  in  pharmaceutical 
arithmetic. 
Dr.  Pile  described  a  package  of  saifron  coming  under  his  notice  in  which, 
covering  nearly  half  an  inch  of  the  entire  surface,  was  a  mass  of  small  worms  ; 
in  the  centre  was  a  mass  (about  \  of  the  whole)  of  small  specks,  which  proved 
upon  examination  lo  be  excrement, of  the  worms. 
Professsor  Maisch  spoke  of  a  sample  of  adulterated  saffron  with  about  10  per 
cent,  of  carbonate  of  lime  fixed  to  the  saffron  with  some  saccharine  matter.  A 
sample  was  also  observed  in  Switzerland  containing  3  or  4  per  cent,  of  the  same 
adulteration.  Mr.  Hanbury,  of  London,  about  the  same  time  examined  a  spe- 
cimen containing  15  or  16  per  cent,  of  the  same  material  fixed  to  the  stigmas. 
These  specimens  had  no  suspicious  appearance  until  placed  under  the  lens  of 
an  ordinary  magnifying  glass,  when  the  fraud  was  easily  detected.  By  throwing 
the  suspected  samples  into  water,  the  carbonate  of  lime  will  fall  to  the  bottom 
of  the  vessel,  while  the  saffron  will  float.  Prof.  Maisch  also  spoke  of  a  sample, 
of  frequent  adulteration, — carthamus  and  calendula  having  been  dyed  with  a 
solution  of  true  sattVon.  This  sample  also  contained  a  large  quantity  of  the 
styles  of  crocus. 
Mr.  McBoring  spoke  of  the  difficulty  of  filtering  a  tincture  of  senega  after 
having  been  evaporated  preparatory  to  making  Compound  Syrup  of  Squill, 
owing  to  the  large  quantity  of  pectin  contained  in  the  senega.  The  question 
was  asked,  whether  bicarbonate  of  potassa  interfered  with  the  tartar  emetic. 
