THE BIOLOGY OF DAILY LIFE. 



CHAPTER II. 



THE LAW OF INTERCHANGE, IN RELATION TO THE BODY IN 

 HEALTH, AND ITS ALIMENT. 



SUBSTANCES belonging to the mineral kingdom 

 (such as carbon, oxygen, hydrogen, nitrogen, phos- 

 phorus), are the ultimate constituents of all animal 

 bodies, and therefore of our human body. This we 

 know and confess. We go further. We confess that 

 we are partly made of metals ; iron, sodium, potas- 

 sium, calcium, and perhaps other metals, are naturally 

 in our bodily structure part of our true texture. 



We may go still further. Without being hypo- 

 chondriacs (like that poor lady who believed she was 

 her own silver tea-pot which she had loved as herself), 

 we may well believe that we are, perhaps, in some 

 sense altogether metallic ! Since oxygen, hydrogen, and 

 nitrogen may (as advanced chemists teach us) be 

 metals in a permanent state of gaseity, I presume 

 their compounds may be called, if we please, alloys. 

 It might be gratifying to regard ourselves or to look 

 upon our neighbours as (like those curious old 

 heathenish bronze images of the Deity) metallic 

 alloys ! 



The thing I want to bring out clearly by all these 

 statements is, that in a chemical point of view we 

 may dismiss the arbitrary distinction between mineral 

 and non-mineral, and even, except as a convenient 

 arrangement for dividing the study of chemistry, 



