190 MADDEX'S ILLUSTRATION. 



With respect to the nature of the metabolic state 

 little can be said. Fletcher speaks of it as " an ever- 

 varying form of existence,"* and Dr. Madden illustrates 

 this by analogy with well-known facts in chemistry. 

 The ordinary chemical affinities are suspended, he 

 says, because of the perpetual change going on. 



" Most chemical combinations require time, and the rate at 

 which the constituents are brought together, and the duration 

 -of their contact, will materially influence the result ; so much 

 so, indeed, that advantage is taken of this fact in the arts to 

 accomplish purposes which would otherwise be unattainable. 

 For example, before calico can be printed, every loose particle 

 of cotton must be removed from the surface, in order that the 

 coloured inks may not run, and damage the clear outline of the 

 pattern. This removal is effected by passing the calico over, 

 and in contact with, a red-hot iron cylinder, and by regulating 

 the rapidity with which the cylinder revolves and the calico 

 passes over it, the intense heat burns off the loose fibres and 

 yet does no injury to the woven cloth. In other words, the 

 changes in the relation of the high temperature and the cotton 

 are too rapid to admit of the fibre combining with the oxygen. 

 Let the rate of revolution be reduced but a very little and the 

 calico would burst into flames. Again, it has been found that 

 certain fulminates can be detonated in contact with gun-cotton 

 without causing the latter to explode ; and experts account for 

 this on the ground of the extreme rapidity with which these 

 fulminates expand, too rapid, indeed, to enable the pyroxyline 

 to initiate its new mode of motion, and hence it remains un- 

 changed. Precisely the same kind of thing occurs in the 

 metabolic state of matter. It can only last so long as rapid 

 .and incessant changes are going on, for which purpose it must 



* And again, "The really organic elements or molecules are pro- 

 bably, under ordinary circumstances that is to say, while the organized 

 being not only possesses the aptitude for life, but manifests life itself 

 never for one instant the same, and are certainly such as to have en- 

 tirely eluded hitherto all our attempts to overtake them." Fletcher's 

 " Physiology," p. 133. ^ 



