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hence, to unload these blood vessels is Indicated as a means of 

 cure. That in the second stage, the distended blood vessels 

 unload themselves into the substance of the lung, by which 

 the ingress of air into the cells is further obstructed, while 

 the viscid secretion of the mucous membrane, simultaneously 

 inflamed, only yields to the air forcing its way through it in 

 successive bubbles ; therefore the crepitant rhonchus or crack- 

 ling is explained ; and hence general antiphlogistic treatment. 

 In the third stage, the fluid effused from the blood vessels be- 

 comes organized, the lung consolidated and rendered firm as 

 liver, and the air cells obliterated by a semi-solid albumen ; 

 hence dulness on percussion ; and the bronchial respiration 

 is heard, owing to the firm substance of the lung having 

 become a better conductor of sound. It is needless to say, 

 that each of these stages of disease requires a diff'erent treat- 

 ment, and that, in the last stage, where the tissue of the lung 

 is disorganized, large depletions would be certain death. It is 

 evident, therefore, that Geology and Chemistry affbrd as much 

 information really practical, as auscultation and pathology do 

 in medicine ; and if by the question of what are practical 

 indications of the value of soils, asked by the Royal Agricul- 

 tural Society, (and I am happy to see several distinguished 

 members of that Society present,) they mean only those 

 of colour, consistence, and vegetation, they will receive an 

 answer as much empyrical, as that given by a physician who 

 declares his diagnosis and mode of treatment in diseases of 

 the chest, from a consideration of only the more external 

 rational symptoms, to the neglect of the physical and patho- 

 logical. 



The fact is, that Agriculture is closely allied to the general 

 sciences, and to exclude any of these from our deliberation, 

 is to contract our view of the grand operations of nature 

 concerned in all her productions. 



It is true that the descriptive sciences always precede the 



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