^Si',mtM-}  Solubility  of  Plumbic  Chloride  in  Glycerin.  371 
•and  then  with  95°  alcohol.  This  anhydride  has  also  a  rotatory  power 
double  that  of  the  glucose,  and  this  power  is  persistent. 
The  author  has  not  yet  obtained  sugar  from  cellulose  sufficiently 
pure  to  be  able  to  compare  it  with  sugar  from  starch  ;  but  he  feels 
certain  that  there  is  no  great  difference  between  their  rotatory  pow- 
ers ;  so  that  their  isomerism  would  not  be  manifested  so  clearly  as  in 
£their  dextrins. 
The  author  proposes  to  investigate  whether  other  sugars  which  are 
/regarded  as  identical  with  glucose — the  glucoses  of  honey  and  of 
fruits,  diabetic  sugar,  &c. — present  the  same  kind  of  isomerism. — 
JPharm.  Journ.  [Lond.~\,  July  4,  1874. 
NOTE    ON    THE    SOLUBILITY   OF    PLUMBIC   CHLORIDE  IN 
GLYCERIN. 
By  Charles  H.  Piesse,  Public  Analyst  for  the  Strand  District. 
Although  it  has  been  noticed  that  plumbic  chloride,  and  some  other 
metallic  chlorides,  are  somewhat  soluble  in  glycerin,  I  have  not  been 
&ble  to  learn  that  any  determinations  of  the  extent  of  their  solubil- 
ities have  been  made.  I  venture  to  think  therefore  that  the  following 
-quantitative  experiments  upon  the  solubility  of  plumbic  chloride  in 
glycerin  may  be  worthy  of  note. 
The  experiments  were  divided  into  two  classes ;  firstly  of  the  solu- 
bility of  plumbic  chloride  in  pure  glycerin  ;  and  secondly  of  its  solu- 
bility in  mixtures  of  glycerin  and  water. 
For  the  first,  pure  glycerin  of  commerce  was  dried  in  a  water-oven, 
until  it  ceased  to  lose  weight ;  about  100  c.c.  of  it  was  then  rapidly 
poured  into  a  dry  bottle  capable  of  holding  about  150  c.c,  and  some 
dry  PbCl2  in  impalpable  powder  added  ;  the  bottle  then  corked,  and 
hermetically  sealed,  was  agitated  for  a  couple  of  days,  being  placed 
in  the  water-oven  during  the  intervals,  so  as  to  maintain  the  tempera- 
ture at  about  100°C.  The  glycerin  was  then  filtered  in  the  water- 
oven,  the  funnel  having  been  previously  heated  therein,  the  filtrate 
being  collected  in  a  weighed  dish.  When  a  quantity  equal  to  about 
300  grains  had  filtered,  the  dish  was  removed,  allowed  to  cool  in  a 
desiccator,  and  then  rapidly  weighed,  a  precaution  which  the  very 
hygroscopic  character  of  glycerin  renders  imperative.  The  weighed 
filtrate  having  been  washed  into  a  beaker,  some  dilute  sulphuric  acid 
was  added,  the  precipitated  plumbic  sulphate  being  collected  and 
