in relation to Disease, 53 



results, but all requiring revision and extension by fur^iher ex- 

 periment. We still have no averages sufficient to shew the re- 

 lative frequency of positive or negative states of the body ; — 

 still less what determines this difference, or the changes taking 

 place in the same person.* And this involves directly the 

 question as to manner of relation with the electricity of the 

 atmosphere ; one made less difficult, perhaps, since the saga- 

 city of Faraday has reduced all the phenomena of induction to 

 functions of the conducting power ; but still requiring much 

 care and research for its complete solution ; and a regard, not 

 merely to the changes of state within the body, but to those 

 also ever occurring in the positive or negative conditions of the 

 atmosphere without; of which the comparative excess of positive 

 electricity during the day may be taken as a well marked ex- 

 ample. 



I have dwelt so far in detail on this part of the subject of 

 the chapter, as being that on which our knowledge is most de- 

 ficient ; and from persuasion also of its future importance in 

 solving many obscure questions in pathology. I might further 

 plead its obvious connexion with all the uses, which may even- 

 tually be ascertained of electricity as a remedy in disease ; a 

 point where it must be owned that much successful research 

 is needed, to remove that imputation of failure which has been 

 the result of the partial and often abortive trials hitherto made. 



Throughout the whole of this chapter, I have been consider- 

 ing the influence on the body of those atmospheric conditions 

 which are commonly termed weather ; exclusively of all chemi- 

 cal changes in the air itself ; of the admixture of other gases ; 

 or of the presence of ingredients of animal or vegetable origin, 

 forming the miasma of disease. Even with these exclusions, 

 and merely touching on the several parts of the subject, it will 

 be seen how vast is its extent, and how important its relations 

 to the history of disease. My principal object has been to in- 

 dicate the latter ; and to suggest some of the topics on which 

 more complete knowledge is to be desired. Here, as already 

 remarked, the progress of physical science is ever lending fresh 



* Tlxe experiments of my friend Professor PfafF of Kiel, in conjunction 

 with Ahrens, are more complete than any others I know on this subject. 



