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Before closing this chapter I would like to return to my point 

 of departure: the apparent independence of symptoms and the 

 underlying disturbance. It seems natural that one should be 

 inclined to connect an increased function with an improved energy 

 supply, an excess of £*, and a decreased function with the oppo- 

 site. However, things are more likely to be the other way round. 

 To use a crude com.parison: if a car runs too fast downhill, this is 

 more likely to be due to faulty brakes than to an improved motor. 

 Thermodynamically, all biological reactions are "downhill" reac- 

 tions, that is, go with a decrease of free energy, the driving force 

 of chemical reactions being the trend of any systems to decrease 

 their free energy. It is possible to "enforce" on a substance an 

 increased free energy content, make it go "uphill," but in this case 

 another substance has to go "downhill" even lower to pay the 

 bill. Biological reactions which have to be fast have to be "down- 

 hill," that is go with an expenditure of free energy, "downhill" 

 being faster than "uphill." So if the contractile matter or the mem- 

 branes of the muscle fiber spend free energy in function, they have 

 to be reenergized after and then kept in the high-energy-resting- 

 state to be ready for renewed action. The slower "uphill" work of 

 reenergization is done after completed action, when it can be done 

 at ease, as the recharging of an accumulator. The active state 

 will thus be mostly the low energy state, the energy having been 

 spent in that action. So, for instance, the low energy state in 

 muscle must be the contracted state, energy having been spent to 

 produce work. Similarly, the low energy state of the membrane 

 has to be its discharged state. An impaired energy supply and 

 reenergetization will cause the systems to persist in the active state. 

 So, for instance, if the supply of energy to the muscle membrane 

 is impaired the fiber will have difficulty in raising the membrane 

 potential above the critical value and the muscle will have a strong 

 tendency to drop back into the contracted state. The nervous end 

 plate which would have fired but once in case of a normal resting 

 potential may fire repeatedly, producing a myotonic behavior in 



