APPENDIX E. cxvii 



The old notions as to the 'specific' nature of cancerous 

 and tubercular products are supported, therefore, neither 

 by the anatomical characters of the growths, by their mode 

 of origin, nor by their mode of distribution ; and the 

 known facts concerning the hereditary transmission of a 

 tendency to the formation of such products are certainly 

 not more explicable in accordance with the old hypothesis 

 than they are by the more modern view. Moreover, the 

 history of these local so-called ' specific ' growths, as others 

 have in part indicated, will be found to throw much light 

 upon the history of general so-called * specific ' affections, 

 and their mode of distribution through communities, or from 

 individual to individual 1 . 



Epidemic and acute specific diseases have many cha- 

 racters in common ; they constitute a family the members 

 of which are united by a certain bond of unity, though 

 at the same time they are, in other respects, strikingly dif- 

 ferent from one another. The ' general ' character of the 

 symptoms originally gave rise to the notion that these 

 affections were in the main dependent upon changes in 

 the nature and quality of the blood. This view is still the 

 one most commonly entertained, and the one which seems 

 most likely to be true. But seeing that particular sets of 

 symptoms recur with as much definiteness as individual 

 differences of constitution will permit, we have a right to 

 believe that the changes in the blood however induced 

 and of whatsoever nature they may be are definite and 

 peculiar for each of these diseases. The successive changes 

 in the blood which are the immediate causes of the phe- 

 nomena of small- pox, must be quite different from those 

 giving rise to the morbid state known as typhoid- fever. 

 Variable as these several groups of symptoms are amongst 



' 1 See Dr. Morris, 'On Germinal Matter and the Contact-Theory,' 

 1867. 



