THE MATERIAL RESOURCES OF LIFE. 339 



developed the malady which were born toeless ? I regret, on closing 

 this pajDer, not to be able to take the psychological aspect of the ques- 

 tion, because it is very interesting in a forensic point of view, and as 

 bearing on the question of responsibility. 







THE MATEEIAL EESOUECES OF LIFE.' 



By albert B. PRESCOTT. 



TO be able to live, in any way known to us, it is indispensable to 

 have a body. And, as living bodies come by growth and con- 

 tinue by nourishment, it is first necessary to have materials whei*eof 

 bodies can be made and renewed and kept in warmth and strength. 

 Just these materials, with permission of the reader, we will try to take 

 account of, as resources of life. Life is not maintained " by bread 

 alone ; " other needful resources being known to physical science, and 

 still other resources greater than all being recognized by their results 

 in life ; but we have the bread alone, as enough, certainly, to be con- 

 sidered in the present article. 



Living things are in very deed made of "the dust of the earth ;" 

 but it is by no means all of the dust of the earth that serves this 

 purpose. We have to distinguish between substances out of which 

 organized instruments of life can be made, and a much larger number 

 of substances never used in the making of these instruments. 



We have it in mind that matter is made up of sixty-three simples. 

 At all events, the earth's crust and air are constituted, substantially, 

 of these sixty-three sorts of atoms, and, as a good many of the same 

 are already revealed in the sun and stars by the spectroscope, it is 

 likely that they are the chief elements in the universe of matter. Of 

 the sixty-three, certain elements, found only in very small quantities, 

 appear to be of subordinate importance in that part of the universe 

 under our immediate observation, Avhatever purposes they may fulfill in 

 other earths or in the centre of our own, or at other epochs. Others 

 of the elements bear an important part in the structure of the globe 

 or in the uses of mankind, but are not organizable materials, and they 

 are not in our present consideration. Of the sixty-three, only four- 

 teen or fifteen swij^les, about one-fourth of those known to us, are used 

 in the construction of plants and animals. These, then, are before us, 

 as the elemental resources of life. 



It will be understood that the tissues are not built directly of these. 



fourteen elements, but of their chemical compounds. Each one of 



these compounds is a definite substance in external character distinct 



from its constituents, as, in a familiar example, water is distinct from 



1 An address given before the Detroit Scientific Association, December 13, 1876. 



