us well as the greater part of those which are called local. It is by means 

 of them, and through these kinds of organic insurrections, if we may be 

 permitted to use that expression, which perfectly expresses our meaning, 

 that nature struggles with advantage, and rids herself of the morbific 

 principle, or of the cause of the disease; and the art of exciting and di- 

 recting these actions, furnishes the materials of the most important doc- 

 trines of the practice of medicine. I have used the terms excite and di- 

 rect; for it is necessary at times to increase, at others to diminish their 

 intensity and force, and on some occasions to excite them, when nature, 

 overwhelmed under disease, is almost incapable of re-action. This last 

 circumstance belongs to the diseases of the most dangerous kind, if we 

 include those in which the efforts of nature, though marked by a certain 

 degree of energy, are without connection, or consent, and frustrated by 

 their want of coherence. The character of these affections was first 

 well expressed by Selle, who substituted, for the term malignant, which 

 used to be applied to them without any precise meaning, that of ataxic,* 

 which points out very correctly, the want of order, and the irregular suc- 

 cession of their symptomsf. 



A knowledge of symptoms is of the highest importance in the practice 

 of medicine!. When we wish to avert an irritation fixed in a diseased 

 organ, experience and observation prove, that it is on the organ which 

 bears to it the closest sympathetic connexions, that it is useful to apply 

 medicines intended to excite counter-irritation. 



This might perhaps be the fittest place to inquire into the nature of 

 those concealed relations which draw men together, and of those aver- 

 sions which prevent their union ; to discover the causes of those secret 

 impulses which lead two beings towards each other; and force them to 

 yield to an irresistible propensity. We might inquire into the reason of 

 antipathy, and in a word, establish the complete theory of moral sen- 

 timents and affections. Such an undertaking is greatly above our 

 strength, and besides, does not absolutely belong to our. subject. It would 

 require a considerable time, and whoever should undertake it, would be 

 in considerable danger of losing his way at every step, in the extensive 

 field of conjectures. 



* a.r<t&t, confusion ; from a, priv. anil TAC.IS, order. Godman. 



j Symptomala ncn'osa, nee inter se, neqne causis manifestis rcspondentia. Ordo tert. 

 actatse, C. G. Selle. Rudimenta pyretologix methodic*. 



t This information may be obtained by consulting 1 the works of the ancients, and 

 especially of Hippocrates, who appears to have felt all the importance of this subject. 

 Among the moderns, Vanhelmont, Baglivi, Rega, Whytt, Hunter, Barthez, and Bichat, 

 have collected on this subject, a great number of facts obtained from experiments on 

 animals, and especially from observations on diseases. Authors Note. 



That law of the animal oeconomy, termed " sympathy or consent of parts," is a very 

 important one, and has hitherto been too much overlooked in our speculations respect- 

 ing- the phenomena of health and disease. There are indeed, not wanting some, who 

 have aflected scepticism as to the very existence of such a law True it is, that, at pre- 

 sent, we have no very distinct intelligence relative to the nature of the principle ; but 

 are we on this account to question its existence ? With equal reason might we doubt 

 of the sensibility or irritability of the body. By whom has the precise nature of either 

 of these qualities of vital matter been demonstrated ? Yet we are persuaded of their 

 existence from the phenomena which they exhibit, and it is by the same description of 

 evidence that we ar*, or ought to be, assured of the existence of sympathy. 



" Causa latct, vis est noiissima." 

 Of the manner in which sympathetic impressions are extended as well as of the cause 



