ON  SOME  POINTS  OF  CHEMICAL  THEORY,  ETC. 
395 
the  general  principle,  that  the  material  by  which  our  bodies  are 
sustained,  may  be  conveniently  arranged  under  the  heads  of 
blood-producing  food,  and  food  which  is  principally  consumed, 
during  the  process  of  respiration,  in  generating  animal  heat, 
The  blood-producing  food,  consisting  chiefly  of  albumen,  fibrin 
and  casein,  contains  nitrogen ;  while  the  heat-producing  food  is  de- 
void of  that  element.  Very  complicated  formulae  are  assigned  to 
the  blood-producing  principles,  giving,  according  to  some  authori- 
ties, more  than  one  hundred  equivalents  to  two  of  their  elements, 
namely,  carbon  and  hydrogen.  Such  formulae  cannot  be  sup- 
ported by  analysis  with  any  show  of  probability.  Nevertheless, 
there  are  chemists?  who  take  these  improbable  formulae  as 
proved;  and  venture  to  trace  the  transformations  which  the 
blood-producing  principles  of  the  food  undergo,  during  their  con- 
version into  blood.  Thus,  they  say,  that  casein,  with  a  certain 
proportion  of  water,  may  yield  blood-albumen  and  chondrin,  the 
latter  being  the  principle  of  cartilage;  and,  again,  that  two  equiv- 
alents of  albumen  and  two  of  water  are  equal  to  one  equivalent 
of  blood-fibrin,  one  equivalent  of  choleic  acid,  and  one  equivalent 
of  gelatin.  The  equations  here  given  are  true  equations,  on  the 
assumption  that  the  composition  of  the  substances  concerned  is 
correctly  represented  ;  but  this  assumption  is  wholly  gratuitous. 
Admitting,  however,  that  the  analyses  are  correct,  can  it  be 
believed  that  equations  like  these  represent  the  truth  of  nature  ? 
These  chemists,  drawing  on  their  fancy,  do  not  hesitate  to  make 
any  transformation  that  may  suit  their  theoretic  views.  If 
they  have  too  much  oxygen  to  suit  their  views,  oxygen  is  alleged 
to  be  given  off  ;  if  there  is  present  too  much  of  both  oxygen  and 
hydrogen,  then  water  is  formed ;  and,  if  carbon  is  redundant, 
they  do  not  hesitate  to  say  that  the  portion  in  excess  is  remov- 
ed, in  the  form  of  carbonic  acid,  by  the  oxygen  of  the  air  !  This 
scientific  facility  reminds  me  of  an  ancedote  which  is  related  of 
one  of  our  commissioners  of  patents,  who  was  in  office  about  the 
beginning  of  the  present  century.  He  was  a  man  of  general 
information,  but  had  no  pretensions  to  a  knowledge  of  science; 
and  to  him,  in  his  own  opinion,  every  thing  was  easy  to  accom- 
plish. Being  simple-minded  and  credulous,  he  was  easily  im- 
posed upon.  A  wag  applied  to  him  for  a  patent  for  making 
boards  out  of  sawdust.    Oh  !  my  friend,  said  the  commissioner, 
