238 
Impurity  in  Chloroform. 
(  Am.  Jour.  Puarm. 
\       May,  1892. 
instance,  i  has  been  found  0-3762.  Such  a  solution  is  quite  viscid, 
and  the  slight  depression  in  the  value  of  i  is  no  doubt  due  to  the 
departure  from  perfect  fluidity. 
The  account  which  we  give  of  the  solution  of  cane-sugar  in  water 
is  as  follows : 
Up  to,  and  no  doubt  considerably  beyond,  a  strength  of  105  grms. 
sugar  in  the  litre,  these  sugar  solutions  are  mixtures  of  fluid  sugar 
(specific  gravity  1-634)  and  water;  and  they  have  exactly  the  same 
volume  as  the  water  and  sugar,  measured  separately.  Very  strong 
and  viscid  solutions — which,  in  truth,  are  not  quite  perfect  solutions 
— exhibit  a  very  slight  departure  from  absolute  uniformity.  They 
are  mixtures  in  which  the  density  of  the  sugar  is  a  little  lower,  viz: 
r6o6,  which  has  been  recognized  as  the  density  of  solid  sugar.  On 
calculation  it  comes  to  this,  that  in  passing  from  the  liquid  to  the 
solid  state  there  is  a  slight  expansion,  viz  :  about  one-fiftieth.  In 
the  viscid  solution  we  find  the  slightly  expanded  sugar ;  but  in  the 
dilute  and  more  fluid  solutions  the  fluid  sugar  is  found  with  its 
density  1-634. 
There  is  similarity  and  dissimilarity  between  saline  solutions  and 
solution  of  sugar.  Similarity,  inasmuch  as  i  is  fairly  constant  over 
a  great  range  of  strengths  in  both  cases;  dissimilarity,  since — 
whilst  sugar  solutions  exhibit  no  marked  contraction — saline  solu- 
tions show  a  very  decided  contraction.  In  the  sugar  case  i  —  i,=  o, 
but  in  the  saline  case  i  —  z,  —  C  ;  and  C  has  a  considerable  magni- 
tude. 
The  view  which  we  take  of  saline  solutions  is  that  they  are  mix- 
tures of  fluid  hydrates  with  water,  and  that  the  fluid  hydrate  simply 
diffuses  into  the  water,  or  mixes  with  the  water,  without  changes 
of  volume  of  any  kind. — Chem.  News,  March  n,  1892,  p.  122. 
IMPURITY  IN  CHLOROFORM.1 
By  D.  Brown,  F.C.S. 
Statements  have  been  made  which  ascribe  injurious  effects  to 
impurities  in  chloroform,  but  I  am  not  aware  of  a  single  instance 
where  these  effects  have  been  traced  to  their  presence.  In  the 
absence  of  reliable  information  regarding  the  chemical  or  physiolo- 
gical action  of  the  substance  other  than  chloroform  which  are 
1  From  Phar.  Journal  and  Transactions,  March  19,  p.  769, 
