9«  Practical  Notes.  { ^'"Ma^'issr"'' 
The  reader  will  observe  that  I  have  followed  the  formula  of  the 
Pharmacopoeia  for  making  solution  of  chlorinated  soda,  substituting 
sulphate  of  zinc  for  carbonate  of  sodium,  even  the  same  quantities 
being  used.  This  is  on  account  of  the  similarity  of  molecular  weight. 
Theoretically,  the  solution  of  the  zinc  salt  made  by  this  process  should 
be  stronger  than  the  soda  solution,  as  there  is  more  zinc  in  24  ozs. 
of  the  sulphate  than  there  is  of  sodium  in  the  same  weight  of  carbon- 
ate, the  latter  salt  containing  10  equivalents  of  water  to  7  of  the 
former. 
Coloring  for  Tooth  Powder,  etc. — An  unobjectionable  color  for  tooth 
powder  can  be  made  by  dissolving  1  oz.  of  the  best  carmine  in  6  fluid- 
ounces  of  stronger  solution  of  ammonia,  and  adding  this  to  a  portion 
of  the  precipitated  chalk  in  a  large  mortar,  using  sufficient  quantity  to 
absorb  the  liquid.  This  is  triturated  with  more  of  the  carbonate  of 
calcium  until  enough  is  added  to  bring  it  to  the  state  of  powder.  This 
is  then  allowed  to  dry,  and,  when  free  from  the  smell  of  ammonia, 
mixed  with  the  other  ingredients  of  which  the  dentrifice  is  composed. 
The  quantities  given  are  sufficient  to  give  a  brilliant  pink  tint  to  thir- 
teen pounds  of  tooth  powder.  By  making  a  solution  of  carmine  in 
ammonia  a  more  thorough  diffusion  of  color  is  effected,  and  1  oz.  of 
carmine  used  in  this  way  will  be  equal  to  about  one  and  three  quar- 
ter ounce  when  used  as  a  powder. 
Cleaninrj  Mortars,  Slabs,  etc. — Mortars  in  which  oil,  balsam  or 
grease  have  been  mixed  should  first  be  thoroughly  scraped  with  a  spa- 
tula, then  wiped  out  with  paper,  next  with  a  piece  of  cotton  batting 
slightly  moistened  with  spirits  of  turpentine,  and,  lastly,  with  cotton 
moistened  with  a  little  soap  liniment,  and  washed  with  water.  By 
this  treatment  tar,  oil,  grease,  petroleum,  balsams,  iodoform,  asafoetida 
and  resins  can  be  effectually  removed  and  much  time  and  annoyance 
saved.  Stains  from  iodine  are  best  removed  by  rubbing  a  few  grains 
of  iodide  of  potassium  and  a  very  small  quantity  of  water  together, 
which  forms  a  concentrated  solution  in  which  iodine  is  soluble.  For 
permanganate  of  potassium  stain  use  muriatic  acid.  Indigo  will  be 
removed  by  strong  sulphuric  acid. 
2' he  Administration  of  Cod  Liver  Oil. — So  much  has  been  written 
upon  this  subject  that  the  reader  might  think  that  the  subject  has  been 
exhausted  by  this  time.  However  this  may  be,  I  do  not  remember 
ever  having  seen  the  following  method  suggested. 
That  this  substance  possesses  valuable  and  special  properties  not 
