106 THE METAMORPHOSES OF MATTER. 



with organisation, are raised to the dignity of life and its 

 attendant death. 



To trace the metamorphosis of these four elements, com- 

 bining, separating, recombining, living, dying, then springing 

 into life only to die and live again, is only possible to the 

 chemist. Neither of these elements can exist alone in any 

 living form. Oxygen and hydrogen always unite together 

 when they can, the result of union being water. Eetrospect 

 and calculation alone can bring into evidence the enormous 

 extent to which the fluid water enters into living beings, and 

 is necessary to the condition of vitality. The loss of weight 

 experienced by all animal and vegetable bodies under the pro- 

 cess of desiccation is always considerable, in some cases enor- 

 mous. Even the materials of an adult human body lose at 

 least three-fifths when wholly deprived of their constituent 

 water; and medusae, or marine jelly-fish, when dried, shrivel 

 almost into nothing ; water constituting at least ninety-nine 

 hundredths of their miscalled substance. 



Of all the metamorphoses that the four chief elements of 

 living things can undergo, those of carbon are the most re- 

 markable. It is curious enough to know that charcoal and 

 the diamond are one and the same element another example 

 of allotropism, by the way, or existence of one element under 

 two forms. But the metamorphoses of carbon by combination 

 are still more extraordinary when united with hydrogen ; 

 sometimes in varying quantities, at other times in identical 

 percentage quantities ; generating results, nevertheless, which 

 are diverse amongst each other, owing to a sort of complex 

 allotropism.. Carbon is the very Proteus of creation. United 

 with hydrogen in one proportion (or rather perhaps in one of 

 several possible proportions), it becomes ordinary illuminative 

 gas. Combination effected with hydrogen in other propor- 

 tions, the result may be oil or fat :. then consider the all but 

 innumerable varieties of oily and fatty bodies ! Carbon and 

 hydrogen joined again in wedlock, we have the oils of turpen- 



