399 



power of motion, and yet with the same rate of actions: in one per- 

 son a lumbar abscess shall form, in another a tubercle in the brain, 

 in another an exostosis or a node of the tibia, in another a mortifica- 

 tion of the toes, in another a gall-stone, in another the conversion 

 of a kidney into fat, in another dropsy, in another calculus of the 

 kidney, bladder, or prostrate gland, in another ossification of the 

 aorta, in another rheumatism, in another necrosis, in another ulcer of 

 the leg connected with varicose veins, &c. Then, say they, the local 

 powers of action are not the same. Before this can be asserted, a 

 test should be proposed by which we might estimate their difference, 

 so far as they can be judged of by the pulse in the respective seats 

 they are all the same, or they might in several examples be found 

 the same; and if pus is formed and variously modified, and calculus 

 is formed, and the textures in one instance preserve their integrity, 

 and in another ulcerate, and in another mortify, and in another pro- 

 duce chalky depositions about joints, and in another throw out a 

 preternatural growth of bone, and in another produce an enormous 

 steatomatous tumour, in another a schirrous tumour endowed with 

 all its predisponent propeities, &c. it may be guessed that these 

 instances shew the agency of properties which are not comprised in 

 an increased or diminished power of action, seeing, also, and setting 

 aside other proofs, that the power of motion estimated by the only 

 test which can be proposed, may be in all these insstances the same. 



22. Others there are who faucy they explain diseases by calling 

 them associated motions, catenated movements, associated sensations, 

 &c. This jargon can scarcely be meant to designate a causation of 

 disease, it is an attempt at a classification (or else it is an attempt at 

 nothing) upon grounds so absurd as to be altogether below a com- 

 ment. We may make motion and sensation a general test of the 

 presence of disease, as there is no disease which does not either affect 

 motion or produce sensation of some kind ; but different states of 

 disease may be connected with the same movements (as in the circu- 

 lation, for example,) or with the same sensations. We form our 

 opinion of the nature of disease frequently from the motions, or the 

 sensations of its seat ; but the circumstances of sensation and motion 

 are only tjie symptoms which indicate particular states of disease 

 upon analogy; that is, because such sensations have been found to 

 accompany certain states of disease. The instances in which a single 

 symptom can stand as the representative of a disease are very rare: 

 perhaps there is no disease which may be defined without the 

 enumeration of many symptoms; symptoms are the sensible results 

 of invisible changes, and they become in turn the causes of disease, 

 as in those examples in which certain symptoms produce the conse- 

 quences of related disease, as a pulse of 140 may be produced by a 

 compound fracture, and the brain in this case, unable to sustain this 

 vehement circulation, exhibits under it the phenomena of phrenitis, 

 as delirium, &c. 



23. There is one other doctrine, which, as it is adopted to some 

 extent, appears to require a notice. The doctrine in effect is this. 



