FRENCH  AND  ENGLISH  WEIGHTS  AND  MEASURES.  445 
As  a  preventive  of  disease,  ozone  can  only  act  by  destroy- 
ing organic  animal  poisons,  in  which  respect  it  may  be  compared 
with  the  substances  I  have  more  than  once  named.  With  re- 
gard to  the  disinfecting  and  deodorizing  powers  of  ozone,  I 
would  refer  you  to  the  opinions  of  the  late  Dr.  Barker,  con- 
tained in  the  Hastings  prize  essay  for  1865.  The  subject  of 
comparison,  and  indeed  the  whole  subject  of  deodorizing  and 
disinfecting,  is  there  so  admirably,  so  exhaustively  discussed,  as 
to  leave,  it  seems  to  me,  nothing  further  to  be  said  on  the  sub- 
ject. 
Lastly,  as  a  remedy.  In  the  form  of  ozonized  oil,  of  ozonized 
ether,  and  ozonized  water,  it  once  more  ranks  with  a  similar 
combination  of  remedies,  containing  chlorine,  bromine,  and 
especially  iodine.  Whether,  in  any  respect,  it  may  prove  to 
have  greater  advantages  than  the  last  named  trusty  and  ready 
agent,  can  only  be  conclusively  arrived  at  by  determining  whether 
it  will  do  what  iodine  will  not  do,  and  this  can  only  be  decisively 
made  out  by  applying  to  it  the  test  of  inductive  philosophy — >a 
rigid  exclusion  of  all  that  is  ineffective. — Amer.  Journ.  Med. 
Sci.,  July,  1868.,  from  Med.  Press  and  Circular,  Jan.  15,  1868. 
RELATIVE  VALUES  OF  FRENCH  AND  ENGLISH  WEIGHTS 
AND  MEASURES. 
By  A.  A.  Fesquet. 
I  see  in  the  column  of  Notes  and  Queries  (American  reprint, 
March,  1868)  that  one  of  your  readers  wishes  some  calculations 
showing  the  relative  value  of  French  and  English  weights  and 
measures.  Tables  for  this  purpose  are  to  be  found  in  many 
technical  works,  but  I  think  they  are  not  so  complete  as  those  I 
join  to  this  letter.  You  will  see  by  the  number  of  different  values 
of  the  gramme,  and  of  the  carat  weight,  that  "  the  doctors  or  the 
standards  disagree." 
The  value  I  have  adopted  for  the  gramme  is  15*438395  troy 
grains,  calculated  from  1  pound  avoirdupois  =  7000  grains  = 
453*4148  grammes. 
It  may  be  that  these  data,  or  my  calculation,  are  incorrect ; 
if  so,  I  wish  to  be  corrected..  It  would  be  a  satisfaction  to  many 
