RESEARCHES  ON  THE  DIFFUSION  OF  FLUORINE. 
43 
read  extracts  from  a  letter  from  Dr.  Baikie,  now  engaged  in  ex- 
ploring the  Niger,  in  which  that  gentleman  stated  that  he  had 
met  with  an  electric  fish  in  Fernando  Po,  and  which  Sir  J.  Rich- 
ardson believed  was  identical  with  the  Malapterurus,  which  had 
been  described  by  Dr.  Wilson,  from  the  coast  of  Old  Calabar, 
The  natives  called  this  fish  the  Tremble-fish — London  Pharm, 
Journ.  October  1857. 
RESEARCHES  ON  THE  DIFFUSION  OF  FLUORINE. 
By  M.  J.  Nickles. 
From  the  whole  of  my  researches,  the  following  conclusions  may 
be  drawn : — 
I.  Fluorine  exists  in  the  blood,  in  very  small  quantities, 
II.  There  is  also  some  in  the  urine. 
III.  There  is  also  fluorine  in  the  bones,  but  much  less  than 
has  been  said ;  according  to  Berzelius,  100  grammes  of  the  earthy 
matter  of  the  bones  contain  3  grammes  of  fluoride  of  calcium ; 
with  the  new  means  of  investigation  which  I  make  known,  we 
find  that  there  is  scarcely  5  centigrammes  of  this  fluoride  in  1 
kilogramme  of  osseous  substance. 
IV.  The  sources  from  which  the  animal  organism  derives  the 
fluorine  which  it  may  require,  are 
1.  Drinkable  waters. 
2.  Vegetable  substances, 
Both  contain  it  in  such  small  proportions  that  it  is  necessary, 
in  order  to  obtain  traces  of  it,  to  operate  on,  at  least,  I  kilo- 
gramme of  ash  and  on  the  product  of  the  evaporation  of  several 
quarts  of  water. 
3.  Accidentally,  also,  the  organism  may  derive  fluorine  from 
mineral  waters,  all  of  which  contain  fluorides  in  very  consider- 
able quantity  as  compared  with  drinkable  waters. 
4.  This  circumstance  appears  to  explain  the  efficacy  of  certain 
mineral  waters,  containing  only  a  small  quantity  of  mineral 
matters,  such  as  the  waters  of  Plombieres,  Mont-Dore,  Soulz- 
bad,  &c. 
5.  The  water  of  the  Seine  taken  at  Paris,  and  the  water  of 
the  Rhine  taken  at  Strasbourg,  are  those  which  contain  the 
least  fluorine. 
