ON  THE  SOURCE  OF  MUSCULAR  POWER. 
31 
rate  the  solution,  treat  the  residue  with  water,  add  solution  of 
soda,  §hake  the  mixture  with  ether,  and  let  the  latter  evaporate 
spontaneously.  Conia  is  distinguished  from  nicotina  chiefly  by 
its  odor,  its  sparing  solubility  in  water,  and  its  comportment  with 
chlorine  water,  and  bichloride  of  platinum. 
ON  THE  SOURCE  OF  MUSCULAR  POWER. 
By  E.  Frankland,  Ph.  D.,  F.  R.  S. 
At  the  conclusion  of  an  elaborate  paper,  Dr.  Erankland 
remarks  : 
We  thus  arrive  at  the  following  conclusions : — 
1.  The  muscle  is  a  machine  for  the  conversion  of  potential 
energy  into  mechanical  force. 
2.  The  mechanical  force  of  the  muscles  is  derived  chiefly,  if 
not  entirely,  from  the  oxidation  of  matters  contained  in  the 
blood,  and  not  from  the  oxidation  of  the  muscles  themselves. 
3.  In  man  the  chief  materials  used  for  the  production  of 
muscular  power  are  non-nitrogenous ;  but  nitrogenous  matters 
can  also  be  employed  for  the  same  purpose,  and  hence  the 
greatly-increased  evolution  of  nitrogen  under  the  influence  of  a 
flesh  diet,  even  with  no  greater  muscular  exertion. 
4.  Like  every  other  part  of  the  body,  the  muscles  are  con- 
stantly being  renewed ;  but  this  renewal  is  not  perceptibly  more 
rapid  during  great  muscular  activity  than  during  comparative 
quiescence. 
5.  After  the  supply  of  sufficient  albuminized  matters  in  the 
food  of  man  to  provide  for  the  necessary  renewal  of  the  tissues, 
the  best  materials  for  the  production,  both  of  internal  and  ex- 
ternal work,  are  non-nitrogenous  matters,  such  as  oil,  fat, 
sugar,  starch,  gum,  &c. 
6.  The  non-nitrogenous  matters  of  food,  which  find  their  way 
into  the  blood,  yield  up  all  their  potential  energy  as  actual 
energy  ;  the  nitrogenous  matters,  on  the  other  hand,  leave  the 
body  with  a  portion  (one-seventh)  of  their  potential  energy  un- 
expended. 
7.  The  transformation  of  potential  energy  into  muscular 
power  is  necessarily  accompanied  by  the  production  of  heat 
within  the  body,  even  when  the  muscular  power  is  exerted  ex- 
