628 THEORY OF DIGESTION. 



mont, that when gastric juice is taken from the 

 stomach, and kept in viols at the temperature of 

 the body, it converts aliment into chyme ; but 

 that when kept below the temperature of 40, it 

 produced no further change than so much water. 

 3. That the digestive power in man is in propor- 

 tion to the quantity of his respiration, which is 

 augmented by moderate exercise and agreeable 

 emotions, but diminished by repose and the de- 

 pressing passions. 4. I also found that when the 

 stomach is weak, digestion is wholly arrested by 

 drinking half a pint of cold milk during winter, 

 attended with flatulence, colic, and nausea, that 

 lasted for above twelve hours. The danger of 

 drinking cold water when exhausted by over 

 exertion, is well known in warm climates, where 

 it often destroys life suddenly. Dr. Beaumont 

 states, that on giving to St. Martin a gill of water 

 at 55 when the stomach was empty, its tempera- 

 ture was reduced from 99 to 70, at which it 



John Hunter, that the electric columns of the torpedo were largely 

 supplied with blood vessels, and by Dr. Davy, that they are con- 

 nected with the organs of respiration. It may therefore be in- 

 ferred, without departing from the rules of philosophic induction, 

 that such animals have the power of converting at will a portion 

 of the caloric obtained by respiration into the temporary form of 

 electricity. Nor is this more strange, than that the caloric of at- 

 mospheric vapour should be discharged in the concentrated form 

 of lightning. Some have supposed that the lungs are positive, 

 and the stomach negative ; while others have prescribed copper 

 and zinc filings, with dilute nitric acid, with a view of supplying 

 the patient with galvanic electricity. 



