GLEANINGS  FROM  GERMAN  JOURNALS. 
317 
The  proportion  of  inhaled  oxygen  to  that  contained  in  the 
exhaled  carbonic  acid  is  in  hunger  and  with  the  use  of  meat  as 
food  100  :  75;  when  using  carbohydrates,  100  :  120;  in  the 
above  observation,  100  :  73.  The  oxidation  of  the  introduced 
carbohydrates  is  therefore  impossible.  If  we  assume  that  the 
normal  number  of  blood  corpuscles  possess,  in  diabetes,  to  a  less 
degree,  the  power  to  resorb  oxygen,  we  are  enabled  to  explain 
the  symptoms  of  this  disease.  (Sitzungsberichte  d.  k.  bayer. 
Akad.  d.  Wiss.,  1865,  II.,  224—227. 
31agnesia  citrica  sohibilis.  Dr.  Hager  analyzed  the  soluble 
citrate  of  magnesia  prepared  by  Menier,  of  Paris,  and  found,  in 
100  parts,  14  parts  magnesia  and  71  parts  crystallized  citric 
acid  (equiv.  201).  The  formula  is  2MgO,HO,  Ci+8aq.  It  may 
be  prepared  by  dissolving  five  parts  crystallized  citric  acid  in  ten 
parts  distilled  water,  and  adding  one  part  recently-calcined 
magnesia,  or  a  corresponding  quantity  of  carbonate,  diffused  in- 
one  part  of  water  ;  the  filtered  solution  is  then  evaporated  until 
a  pellicle  forms,  and  set  aside,  when  it  partly  crystallizes  and 
partly  congeals.  Thrown  into  water,  the  crystallized  portion 
dissolves  first,  afterwards  the  crystalline  crusts.  It  is  important 
not  to  use  a  trace  of  magnesia  in  excess,  which  would  form  the 
insoluble  neutral  citrate,  and  dispose  nearly  all  the  magnesia  to 
separate  in  this  form.  .Repeated  heating  appears  to  have  the 
same  effect,  and  it  is  advisable  to  boil  the  solution,  without  in- 
termission, to  the  required  point.  (Pharm.  Centralhalle,  1866, 
K.  40.) 
Preparation  of  fruit  syrups.  Mr.  Jessler  states  that  the 
directions  for  their  preparation,  contained  in  the  Pharmacopcea 
Germanise  are  the  best,  yielding  a  syrup  rich  in  color,  possessing 
the  full  flavor  of  the  fruit,  and  being  not  liable  to  become  turbid. 
The  bruised  fruit  is  allowed  to  ferment  for  two  days,  in  cooler 
temperature  for  three  or  four  days,  merely  to  transform  the 
pectin  into  pectic  acid ;  the  juice  is  now  expressed,  heated  to  80 
or  90°  C,  set  aside  for  several  days  in  the  cellar,  then  filtered. 
Thirty  pounds  of  the  filtered  juice  are  poured  over  fifty  pounds 
of  crushed  sugar,  heated  to  boiling  in  a  bright  copper  kettle, 
strained,  and,  while  still  warm,  filled  in  jugs,  which  are  corked, 
sealed,  and  when  perfectly  cool,  repeatedly  shaken.    The  last 
