276 
Varieties. 
(Am.  Jobr.  Pharm. 
1    June  1,  1873. 
For  the  detection  of  sugar  and  glucose  in  glycerin. — To  five  drops 
of  the  glycerin  to  be  tested,  add  100  to  120  drops  of  water,  one  drop 
of  pure  nitric  acid,  and  one  grain  of  ammonium  molybdate,  boil  the 
mixture,  and  in  less  than  two  minutes  it  will  assume  an  intense  bluish- 
green  color  if  any  sugar  or  glucose  is  present. 
In  the  foregoing  table,  A  represents  Price's  patent  glycerin ;  B, 
C,  D,  E,  F,  were  sold  by  Continental  manufacturers  as  double  dis- 
tilled white  glycerin,  a  la  Price,  inodorous,  guaranteed  to  stand  the 
nitrate  of  silver  test  (sp.  gr.  30°  to  31°  B.) ;  G  and  H,  as  refined 
glycerin  (28°  B.  sp.  gr.)  ;  and  I  is  a  sample  of  concentrated  crude 
glycerin  from  Hamburg,  as  exported  for  manufacturing  purposes. 
A,  B  and  H  have  been  exposed  to  strong  sunlight  in  closed  vessels 
for  two  days.  A  was  unchanged,  but  B  and  H  had  the  mousey  odor 
very  fully  developed,  but  without  discoloration. 
It  will  bo  observed  that  there  are  slight  impurities  in  B,  C,  D,  £, 
but  I  think  none  to  prevent  the  majority  of  the  samples  being  used 
in  phaimacy  and  medicine  when  not  intended  for  internal  adminis- 
tration. 
I  consider  that  pure  medicinal  glycerin  should  not  be  affected  by 
nitrate  of  silver,  sulphuric  acid,  oxalate  ammonia,  or  exposure  to 
sunlight,  and  should  be  perfectly  free  from  smell  after  this  treatment. 
— Chemist  and  Druggist,  1873,  April. 
l)arictic0# 
India  Rubber  Varnish. — There  are  many  substances,  among-  them  nitrate  of 
silver,  upon  which  pure  india  rubber  has  no  deleterious  effect.  Now,  as  india 
rubber  dissolves  with  readiness  in  chloroform,  sulphuric  ether,  bisulphide  of 
carbon,  and  caoutchoucin,  and  as  these  solvents,  when  evaporated,  leave  the 
rubber  firm  and  unaltered,  it  is  evident  that  we  have  in  a  varnish  so  composed 
a  means  of  applying  a  coating  of  pure  rubber  of  any  degree  of  thickness  to  the 
inside  of  any  vessel,  such  as  a  photo  bath  composed  of  either  ebonite,  gutta 
percha,  wood,  or  any  other  material  of  a  similar  description.  From  experi- 
ments made  in  this  direction,  using  bisulphide  of  carbon  as  the  solvent,  a  coat- 
ing of  rubber  of  a  good  quality  has  been  obtained,  which  will  answer  most 
effectively  for  preventing  all  contact  between  the  silver  solution  and  the  mate- 
rial of  which  the  bath  itself  is  formed. — Sci.  Amer.,  March  15,  1873. 
Note  on  the  Solvent  Action  of  Glycerin  on  the  Metallic  and  Calcareous  Ole- 
ates,  and  on  Sulphate  of  Lime. — E.  Asselin.— Pure  glycerin,  free  from  lime,  of 
