2io  Selections  from  the  Banish  Journals.  {AmkJa0>u)rl8p76arrn' 
SELECTIONS  FROM  THE  DANISH  JOURNALS. 
BY  HANS  M.  WILDER. 
'Telegraphy  by  means  of  Tuning-Forks. — P.  la  Cour  (Denmark)  has  invented  a  new 
telegraph  apparatus  (June,  1874),1  which  bids  fair  to  play  an  important  role  at  no 
distant  future. .  It  is  based  on  the  fact  that  when  a  tuning-fork,  by  its  vibrations, 
closes  and  opens  an  electrical  circuit,  another  tuning-fork,  connected  with  it  by  the 
wire — provided  it  have  the  same  pitch — will  be  made  to  vibrate.  Any  number  of 
differently  pitched  tuning-forks  may  be  connected  with  others  by  the  same  single 
wire,  and  only  the  corresponding  ones  (the  isochronous)  can  be  made  to  vibrate. 
The  practicability  of  the  above  method  of  telegraphing  was  demonstrated  on  the 
wire  between  Copenhagen  and  Fredericia  (390  kilometers,  about  250  miles).  (The 
description  of  the  instrument,  the  advantages  accruing  from  its  use  and  the  detailed 
experiments  will  be  found  in  "Ann.  de  Chim.  et  de  Phys.,"  1875,  P-  284). — Arch, 
for  Ph.,  1875,  P-  466. 
A  New  Kind  of  Spontaneous  Combustion. — "  Pharm.  Centralh.,"  1875,  No.  25, 
reports  a  case  of  spontaneous  combustion  arising  in  a  box  of  chipped  logwood, 
which  probably  had  been  packed  in  a  moist  state. — Ibid.,  p.  480. 
Arsenic. — Prof.  Binz,  in  Bonn,  calls,  again,  attention  to  Bettendorff's  test  (see 
"Amer.  Jour.  Phar.,"  1871  (xliii),  p.  222)  for  arsenic,  as  the  easiest  for  the  physi- 
cian. Put  a  piece  of  the  suspected  substance  in  a  test-tube,  pour  over  it  concent- 
rated muriatic  acid,  add  a  few  crystals  of  protochloride  of  tin,  and  heat  5  arsenic, 
if  present,  will  be  reduced,  and  thrown  down  as  a  dark-brown  powder. — Ibid., 
p.  483. 
Caoutchouc  in  Affections  of  the  Lungs. — Electuary  of  caoutchouc  has  again  been 
recommended  in  phthisis,  etc.,  by  Drs.  Varick  and  Calver.  Dissolve,  by  macera- 
tion, 30  grams  finely  cut  caoutchouc  in  60  grams  oil  of  turpentine  5  strain,  and  mix 
l\  grams  with  45  grams  of  sugar  and  75  grams  of  honey.  One  teaspoonful  of  this 
electuary  contains  about  0*12  gram  of  caoutchouc.  It  is  said  to  prevent  night- 
sweats,  blood-spitting  and  emaciation. — Ibid.,  p.  495,  from  Fharm.  Centralh.,  1875, 
No.  41. 
Infants^  Food. — Dr.  H.  Muller  has  examined  into  the  quality  of  the  different  kinds 
of  food  for  infants,  and  came  to  the  following  results  :  Liebigs  food  is  somewhat 
difficult  and  tedious  of  preparation,  so  that,  as  a  rule,  the  soup  is  seldom  properly 
made.  The  different  modifications  that  exist  are  much  more  easy  to  use,  but  they 
do  not  keep  as  well,  and  do  not  taste  as  agreeable  as  the  original  food.  One  serious 
objection  is  found  to  Liebig's  food — its  exclusive  use  predisposes  children  to  rachitis, 
since  it  does  not  contain  sufficient  bone  food. 
Nestles  mother  s  milk  and  (still  more,  a  modification  of  it)  Faust  and  Schuster's 
Gottingen  infant  meal,  Dr.  M.  considers  the  best  substitute  for  mother's  milk.  It 
contains  in  100  parts:  n'51  protein  substances,  79*61  carbohydrates,  i*8o  inorganic 
iThe  same  or  a  similar  apparatus  has  recently  been  on  exhibition  at  the  Franklin  Institute,  in  Phila- 
delphia.— Editor  Amer.  Jour.  Phar. 
