APPENDIX. 339 



hastens dissolution. Old Parr and Jenkins do not appear 

 to have fed on a vegetable diet ; and the longevity of Cornaro 

 seems to have depended more on his moderation in diet, than 

 on the quality of his food. Animal food is certainly as easily 

 and as soon, if not sooner, digested : and to state the question 

 of diet fairly, would be to say, in cases where from the liealthy 

 state of the digestive organs, the chylopoietic functions go on 

 perfectly, what difference is subsequently observable between 

 the effects of the mixed, and those of the purely vegetable 

 nutriment ? I was once inclined to attribute much good to 

 the vegetable regimen as general diet; but subsequent ex- 

 periments and observation have made me somewhat sceptical 

 on this point. Animal food appears to afford more nourish- 

 ment, in proportion to its volume, than vegetables. There 

 may, perhaps, be minute differences in the quality of the 

 blood, arising from different kinds of food, which evade all 

 chemical tests ; but, as we know nothing of these, we ought 

 not to be deluded by hypothetical arguments on the subject. 

 As the digestive processes are those of assimilation, the blood 

 seems more likely to be deteriorated by bad chylifi cation and 

 absorption of unassimilated matter, arising from disorder in 

 the organs, than from the quality of the aliment, when the 

 stomach is healthy. In disease, the blood may be altered 

 in composition, from various sources; the liver and other 

 secreting organs not giving out their proper fluid, and these 

 remaining in the blood may alter its properties, and increase 

 and render compound the evil of sympathetic irritation. 



To preserve health, of which we are in actual possession, 

 and to cure disorders when once established, are certainly 

 very different things : in the latter case, various kinds of diet, 

 like medicines, having specific actions arising fpom the nature 

 of the disorder, particular regimen may become necessary, in 



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