436 NATURAL SCIENCE. august. 



open one of the three gates. The frame of a higher animal does not, 

 hke the autocrat's one-horse shay, slowly and equally decay until 

 there is a simultaneous collapse of everything — until each cell is senile 

 and moribund — but the heart or the lungs, or some centre in the 

 brain suddenly gives way. But here, perhaps, more plainly than in 

 other cases, we see that the violence or suddenness of death, on 

 which so much stress has been laid, is the merest accident, due to 

 the complexity of the organism. There has been going on for long a 

 gradual degeneration of the walls of the blood-vessels — a degenera- 

 tion showing itself by an accumulation of fat or of lime — products 

 usually oxydised or excreted, and this slow cellular change has, by 

 weakening the circulation, acted on all the organs of the body, and 

 reacted on itself until some point is reached at which the gross 

 mechanism breaks down. So, in the cases of most causes of death, 

 we can trace back the chain of events until we find that what is said 

 to cause death is only an accidentally last term in a long series of 

 protoplasmic changes ; changes, as in lung diseases, where the lung 

 cells have been gradually decaying, or, as in Bright's disease, where 

 kidney cells have been failing to do their work. 



In short, protoplasmic changes have been going on, and when 

 the results of these have sufficiently accumulated, the gross 

 mechanism is suddenly arrested ; or, more directly, an interference 

 may result when some natural mechanism is accidentally over- 

 stimulated, as when reflex stimulation of the vagus stops the heart, 

 or when a lethal alternating current is switched through the spinal 

 cord ; or again, a poison may paralyse a brain centre, and so the 

 heart or the lungs be stopped. 



It is clear that in all these cases^the modes of death treated of 

 in the medical books — a confusion of ideas exists. The source of 

 this confusion is clearly seen when one finds, for instance, Foster 

 suggesting that the point of death cannot be determined, as it depends 

 on the skill of the experimenter endeavouring to resuscitate a 

 flickering vitality ; or Weismann and Gotte gravely discussing 

 whether there can be death without a corpse, and whether death is a 

 subtle attribute of the metazoa teleologically built up by natural 

 selection into its present form. We have to distinguish between 

 protoplasmic death, and the stoppage of a complicated organism. 



We know with absolute certaint}' that whatever be the details ot 

 the processes going on in a living cell, the sum of the activity is the 

 acquisition of potential energy either indirectly by the transformation 

 of kinetic energy, as in green plants, or directly by the absorption of 

 chemical compounds possessing high heat equivalents — I mean 

 compounds which, if oxydised in a calorimeter, melt relatively high 

 quantities of ice : the change of these chemical compounds into 

 substances that can melt relatively smaller amounts of ice. 

 The difference of heat equivalent represents the work done by the 

 cell, and the waste in doing the work. Protoplasmic death is an 



