1S13.] Imperial Institute of. France. 393 



classes of diseases. In his account of chronic diseases, he shows 

 that the want of nutrition and emaciation are produced more 

 speedily by diseases connected with respiration than with the 

 organs of digestion. He shows the constant relation between 

 certain external forms, and a disposition to peculiar chronic- 

 diseases. Hence he deduces the character of the physiognomy 

 peculiar to each. 



The study of the revolutions natural to these diseases has made 

 him perceive a period within which it is still possible to prevent 

 their formation : different kinds of crises which succeed it, and 

 what may render these crises advantageous or injurious : the 

 different changes of acute into chronic diseases, and vice verse, 

 and the cause of these alternations. 



The determination of the simple affections of which these 

 diseases are composed, or of their pathological elements, ap- 

 peared to him of the greatest importance ; since it furnishes us, 

 in some measure, with the means of simplifying them, by 

 attacking these elements one after another, beginning with the 

 most powerful. This fundamental point of view has enabled 

 him to explain their formation, and to determine in a solid 

 manner the method of treating them ; but for this purpose it was 

 necessary to draw an accurate line between the essential elemen- 

 tary affections and the symptomatic. 



Thus he has risen by degrees to the general phenomena, and 

 has been able to deduce them from a small number of primitive 

 affections. His theory of the formation of chronic diseases 

 reduces itself to the relations of the elementary affections to each 

 other, and to the system of organs which they occupy. 



M. Dumas treats, in a manner which he considers as hew, 

 every thing that regards the general disposition to chronic 

 diseases. He establishes a difference between the constitution 

 arid the temperament, which are sometimes opposed to each 

 other ; and this opposition is the most direct cause of a tendency 

 to chronic diseases. He estimates the influence of time of life 

 by the relation between the elementary affections, from which 

 results a disposition at every age to different kinds of (lis 

 modifications in the diseases common to each age, and changes 

 advantageous or hurtful during the progress of each disease. Me 

 treats of the passions after analogous views. Each of them may 

 be decomposed into a certain number of simple affections, which 

 Metaphysics knows and enumerates. 



Finally, M. Dumas arrives at his last part, which is that of 

 the treatment, lie shows the justice of his doctrine, by making 

 it appear that all the approved methods of treatment are easily 

 reducible to tin- principles which he has established. Me finishes 

 with -onie latere ting observations on hereditary and on incurable 

 . 



In an appendix, .M. Dumas gives several examples of the 



