APPENDIX. 333 



the patients in whom they may occur. As we do not know 

 the nature of the specific stimulants which excite many 

 atmospheric or other diseases, nor any particular counteract- 

 ing antidotes, in medicines, we must be content to prescribe a 

 general mode of conduct to those in health, which, by pre- 

 serving a strong and tranquil condition of body, may avert or 

 mollify the influence of the atmosphere on the constitution, 

 and to endeavour to restore those already disordered, by 

 measures that are generally known to conduce to such a state 

 of health. It may not, therefore, be entirely foreign, to the 

 present subject, to discourse briefly on the mode of preserving 

 the healthy, and of rectifying the disordered, actions of the 

 animal machine. Early rising, good air, and exercise, free- 

 dom from care and anxiety, and temperance of appetite, have 

 been from time immemorial the popular receipts for health 

 and longevity; but the quantity of exercise necessary, the 

 quantity of our food, and the periods of taking it, and its 

 quality, which involves the question of natural diet, must 

 be submitted to a more accurate and physiological scrutiny, 

 which may, in a great measure, explain the ill success of 

 many who labouring under disorder, yet think themselves 

 entitled to health from the observance of an imagined course 

 of temperance. Exercise should be taken to a considerable 

 degree, but by no means when the stomach is full. Various 

 experiments have long ago established it as certain, that 

 digestion is never so well performed, as when a meal is fol- 

 lowed by rest; and carnivorous animals, and, indeed, all 

 those who take in their food in any quantity, rest or sleep 

 after their repast. Exercise, under favourable circumstances, 

 seems to give vigour to the whole system ; and strength 

 appears, to a certain degree, to be commensurate to bodily 

 exertions, and health and spirits are the consequence. Indeed 



