64  Borocitrates  and  their  Preparation.  {^"^ir^issi*'^'"' 
use,  can  be  placed  aside  in  a  small  box.  It  is  useful  for  drawing 
liquors  from  barrels,  for  washing  precipitates,  in  preparing  deod.  tinct.. 
of  oj)ium,  etc. 
7.  The  nipple  can  be  used  where  the  small  neck  of  a  Florence  flask 
does  not  allow  a  double  perforation,  as  in  Fig.  11.  Draw  one  nipple 
over  the  neck,  and  the  other  nipple  over  the  doubly  perforated 
cork,  and  connect  both  nipples  with  a  short  wide  glass  tube,  flanged 
at  both  ends.  In  all  cases  the  top  hole  of  the  nipple  should  be  care- 
fully enlarged,  to  enclose  the  glass  tube  firmly,  and  nipples  with  one 
perforation  only  should  be  used. 
8.  A  very  convenient  pencil  eraser.  Put  the  brown  nipple,  which. 
I  found  to  be  best,  over  the  third  finger  of  your  right  hand  and  hold 
the  pencil  as  usual,  and  you  will  be  quite  astonished  at  the  conveni- 
ence. You  will  never  again  run  about  the  store  to  look  for  your 
eraser. 
9.  As  a  medicine-dropper.  Attach  a  pointed  glass  tube  to  the  top 
of  the  nipple  and  draw  over  the  bottle  containing  the  medicine  (Fig.  2). 
In  using,  squeeze  the  nipple.  In  the  same  way,  it  can  be  used  as  a. 
sprinkler  to  wash  small  precipitates  on  the  filter. 
10.  Cover  for  alcohol  lamp. — Phar.  and  Chem.,  Jan.^  1881. 
THE  BOROCITRATES  AND  THEIR  PREPARATION.^ 
By  Edmund  Scheibe. 
Magnesium  Borocitrates. — Of  all  the  compounds  of  borocitrie- 
acid  the  most  interesting  is  the  salt  of  magnesium,  since  it  was  success- 
fully used  therapeutically  more  than  forty  years  ago  by  Graeger,, 
Beckert^  and  other  physicians  in  cases  of  kidney  disease  and  stone.  A 
subsequent  treatise  Archiv  d.  Pharmacie"  (1866),  cxxvii,  256)  upon 
the  action  of  magnesium  borocitrate  in  calculous  disorders  attributed 
this  to  the  boric  acid,  which  does  not  undergo  any  change  through  the 
secretions  of  the  human  body,  and  is,  therefore,  able  to  exercise  a 
decomposing  action  upon  the  salts  of  uric  and  phosphoric  acids. 
The  correctness  of  this  theory  is  said  to  be  confirmed  by  the  experi- 
ments of  the  author  and  Madsen  ("  Pharmaceutische  Zeitschrift  f. 
^From  a  paper  published  in  the  "  Pliarmaceutische  Zeitschrift  f.  Russ- 
land,"  xix,  514. 
-Magnesia  iista,  30  parts  ;  Acid,  boracic,  100  parts;  Acid,  citric,  60  parts;. 
Acid,  hydrochloric,  (sp.  gr.  1-124),  30  parts. 
