Am  Jour.  Pharm.  [ 
June,  1875.  j 
Varieties. 
or  even  to  softness,  and  then  slowly  cooled,  it  easily  happens  that  the  constituents 
separate  and  form  crystalline  groups.  Reaumur  made  this  experiment  in  the  last 
century,  hoping  to  make  porcelain  out  of  glass,  and  the  product  was  called  Reau- 
mur's porcelain.  Siegwart  and  others,  a  few  years  ago,  although  with  a  different 
view,  made  experiments  on  this  change.  These  experiments  showed  that  this  sep- 
aration takes  place  very  easily  if  the  glass  is  slowly  cooled,  and  that  sometimes  the 
crystalline  portion  becomes  visible,  and  when  this  takes  place  the  glass  is  said  to  be 
devitrified.  From  these  new  experiments  we  may  conclude  that  fused  glass  in  a 
fused  state  forms  a  tolerably  homogeneous  mass,  which  separates  more  or  less  on 
cooling.  If  it  is  cooled  rapidly  to  a  certain  point,  the  separation  does  not  go  so  far, 
and  the  glass  remains  more  homogeneous,  which  may  be  the  cause  of  its  hardness 
on  the  one  hand,  and  of  its  peculiar  way  of  breaking  on  the  other. — Journ.  Applied 
Chem.,  May,  1875. 
Fluorescence  of  Bodies  in  Castor  Oil. — Charles  Horner  states  that  certain 
Tiatural  organic  coloring  matters,  which  exhibited  no  fluorescence  when  in  aqueous 
or  alcoholic  solution,  were  observed  to  fluoresce  brightly  when  dissolved  in  castor 
oil  5  while  other  substances,  possessing  naturally  a  faint  fluorescence,  were  found  to 
have  this  property  considerably  augmented. 
In  this  solvent,  cudbear  exhibited  a  brilliant  orange-colored  light,  and  extracts  of 
logwood  and  camwood  a  powerful  apple  green  fluorescence.  The  well-known 
-fluorescent  light  of  turmeric  solutions  was  increased  in  brilliancy  at  least  threefold, 
and  is  described  as  a  vivid  emerald  green  fluorescence,  comparable  only  with  the  ap- 
pearance presented  by  the  best  uranium  glass  under  similar  circumstances.  It  is 
suggested,  therefore,  that,  in  studying  the  phenomena  of  fluorescence,  advantage 
should  be  taken,  when  possible,  of  the  solvent  property  of  castor  oil. — Scientifc 
Amer.,  April  17,  1875. 
Value  of  Gelatigenous  Tissues  in  Nutrition.  By  Carl  Voit. — The  au- 
thor gives  details  of  a  feeding  experiment  with  ossein  on  a  dog.  The  results,  like 
those  with  gelatin,  show  that  it  eff'ects  a  saving  of  albumin  and  of  fat,  but  cannot  be 
substituted  for  albumin.  10-71  grams  of  ossein  per  diem  reduced  the  daily  loss  of 
nitrogen  from  10*17  grams  whilst  fasting  to  8*4.  Unlike  gelatin,  it  does  not  pro- 
duce diarrhoea.  The  author  recapitulates  the  difterences  of  opinion  between  himself 
and  Hoppe-Seyler.  The  latter  thinks  that  the  consumption  of  albuminous  matters 
in  the  system  is  due  to  the  decay  of  the  cells  and  tissues  5  whilst  Voit  believes  that 
by  far  the  greater  part  is  due  to  the  oxidation  of  the  circulating  albumin  of  the  lymph 
when  this  substance  enters  the  cells  and  tissues,  and  not  to  the  decay  of  the  tissues 
themselves. — Journ.  Chem.  Soc,  Jan.,  1875.  From  Zeitschrift  f.  Biologic,  x,  202 — 
245. 
A  New^  Reaction  of  Essence  of  Mint.  By  C.  Roucher. — If  acetic  acid  of 
about  10  degrees  be  agitated  with  one-twentieth  of  Its  weight  of  essence  of  mint,  a 
feeble  blue  coloration  will  soon  be  observed,  which  gradually  increases  in  intensity. 
Tlie  color  is  of  a  dichroic  character,  being  blue  by  transmission  and  cinnabar-red  by 
reflection.  It  is  not  stable,  but  soon  changes  to  green  and  then  to  yellow. — Journ. 
Chem.  Soc,  April,  1875.    From  J.  Pharm.  Chim.  [4],  xx,  354. 
