330 APPENDIX. 



other things, without being ill. There are persons who can 

 eat all meat but mutton which never digests with them. It 

 may be proper to consider, first, what sort of food is best in 

 health : and, secondly, what may be the medical influence of 

 different changes of diet in cases of disorder. With regard 

 to the first of these questions, little enough can be expected 

 from any hypothesis of the cause of diseases. It is a question 

 to be solved by an accurate examination of facts. We cannot 

 even place much dependence on the analogy of the human 

 structure to that of any other animal; for though the 

 structure of the human organs of digestion most resemble 

 those of carnivorous animals, yet the monkey tribe, which, in 

 many respects, approach nearest in their nature to man, live 

 on vegetable substances. Several writers of physiology have 

 asserted, that those persons who feed on a mixture of animal 

 and vegetable food are stronger and more active than those 

 who subsist entirely on vegetables ; while the advocates for a 

 pure vegetable diet contend, that it produces more tranquillity, 

 and even a more mild and amiable character. These two 

 assertions are by no means irreconcileable, and agree very 

 well with experiments and observations that I have made, 

 which have had a tendency to show that animal food produces 

 more muscular strength and energy, but, at the same time, 

 renders the body more susceptible of irritation. When, to 

 patients who have long subsisted on vegetable food, flesh has 

 been superadded, the pulse has become quicker, the muscular 

 motion more quick and lively, the countenance more highly 

 coloured, and the spirits exhilarated. These effects are strik- 

 ingly conspicuous just after the adoption of the meat, and 

 illustrate the greater degree of stimulus afforded by animal 

 food : and the contrary effects often appear on first taking to 

 vegetables alone. But after a time, in cither case, a very 



