A. E. HILTON ON THE NATURE OF LIVING ORGANISMS. 43 



grappling with, and escaping from each other with inconceivable 

 rapidity, and whirling round the atoms in circular or elliptical 

 orbits. Chemical affinities are now explained as depending upon 

 the quantity of detachable electrons when atoms come into con- 

 tact; and we are told that in all bodies, rare or dense, including 

 the hardest rocks and metals, the activities of electrons are 

 ceaselessly maintained. We almost begin to wonder, not at the 

 abounding life of nature, but that there should be anything in 

 the universe not alive ! Vitality, however, is more than motion ; 

 it is movement co-ordinated, and therefore involves processes of 

 particular kinds. 



From this necessary digression we return to our study of the 

 plasm. Chemically, it is a compound of compounds, exceedingly 

 complex. Carbon in large proportion, oxygen, hydrogen, and 

 nitrogen in lesser degree, small quantities of phosphorus and 

 sulphur, and traces of some half-dozen other substances, all 

 enter into its composition ; but before plasm can be formed from 

 these materials, carbon and oxygen must combine as carbonic 

 acid, hydrogen and oxygen must produce water, and nitrogenous 

 salts must be formed by nitrogen and other elements. Then, 

 by a coming together of these several compounds under r.atural 

 conditions, plasm results, and exhibits the phenomena of life. 



The molecules of plasm are, of course, far beyond the range 

 of microscopic vision ; but, comparatively, they are of enormous 

 size. Each molecule probably contains over a thousand atoms ; 

 but the atoms are very loosely linked together, and being, there- 

 fore, extremely unstable, constantly rearrange themselves in new 

 combinations. Thus the plasm-machinery, intricate as it is, 

 works freely within its limits, and with great adaptability ; but 

 it is liable to be affected by every slightest influence, physical, 

 chemical, or electrical. 



The opposite but equally important characteristic of plasm is 

 its tenacity. Without firmness, as well as elasticity, it could 

 not build up organic structures ; and this firmness is secured 

 by the largely preponderating element of carbon. Organic 

 chemistry is practically the chemistry of carbon compounds , 

 and these we must briefly consider. Carbon, in an almost pure 



