^"^Nov.'i'isS^^™"}      Gleanings  fi^om  the  German  Journals.  557 
of  examination :  1  cc.  is  measured  into  a  tared  stoppered  flask,  the 
weight  of  the  oil  ascertained,  10  cc.  absolute  alcohol  added  to  dissolve 
the  oil  and  agitated  after  addition  of  20  drops  of  an  alcoholic  potas- 
sium hydrate  solution  until  the  odor  of  the  oil  has  entirely  disappeared. 
The  contents  of  the  flask  are  then  dissolved  in  water,  acidulated  with 
acetic  acid  and  titrated  with  to  n.  copper  sulphate  solution  (12*47  gm.  per 
liter).  The  end  of  the  reaction  is  ascertained  by  obtaining  a  red  color- 
ation or  precipitate  if  a  drop  of  the  solution  is  placed  on  blotting 
paper  and  a  drop  of  potassium  ferrocyanide  solution  added.  Each  cc. 
of  the  copper  solution  represents  0'0086  gm.  carbon  disulphide. 
According  to  age  and  quality  of  the  oil  from  8*14  per  cent,  to  41*03 
per  cent,  of  CS2  were  found ;  self -prepared  oil  of  mustard  contained 
from  9*82  per  cent,  to  10*82  per  cent,  diminishing  in  a  year's  time  to 
2-03  per  cent,  (one  specimen  to  0'91  percent.)  of  CS2;  the  artificial  oil 
averaged  10*78  per  cent.  The  origin  of  the  CS2  is  not  definitely  made 
out,  but  the  decomposing  effect  of  steam  and  the  presence  of  KHSO4 
influence  its  formation ;  by  heating  oil  of  mustard  with  KHSO4  an 
increase  of  CS2  from  0*45  to  2*29  per  cent,  was  observed.  The  oil 
obstinately  retains  the  carbon  disulphide,  and  they  can  not  be  separa- 
ted completely  by  distillation.  A  comparative  examination  of  the 
seeds  of  Brassica  nigra  and  Sinapis  juncea  was  made  : 
Ash. 
Soluble  in  Petrol.  Spirit] 
a         Ether  I 
.........    xjsed  in  succession... 
"         Abs.  Alcohol  I 
75  p.c.   "  J 
Nitrosren. 
Brassica 
nigra. 
Sinapis  juncea. 
,  8-47 
p.c. 
7.63  p.  c 
5-04 
4-52  " 
..  1-84 
(t 
1-89  " 
29-37 
li 
30-10  " 
.  0-93 
11 
1-30  " 
0-80 
11 
1-25  " 
6-77 
(( 
640 
4-21  " 
..  061 
i( 
0-54  " 
..  1-89 
a 
1-67  " 
—P.  B.  in  Schwz.  Wchnschrf.  Phrm.,  1888,  277. 
Mel  rosatum. — 1  part  rose  leaves  and  6  parts  boiling  water  are 
mixed  and  allowed  to  macerate  for  24  hours  in  a  covered  vessel.  To 
the  strained  liquid  is  added  9  parts  crude  honey,  and  this  solution 
heated  on  the  water  bath  until  the  precipitate  coagulates,  which,  after 
cooling,  is  filtered  off ;  the  filtrate  is  evaporated  to  a  syrupy  consist- 
ence. The  tannin  of  the  rose  leaves  unites  with  the  albuminous  prin- 
ciples of  the  honey,  and  after  the  removal  of  the  precipitate  a  honey 
