2I 9 



differentiation of individuals from one another, in conse- 

 quence of heredity and variability, includes differences in 

 the structure, functions, quality, and complexion of the skin, 

 which are not only more or less hereditary, but which, how- 

 ever normal they may appear, will more or less predispose 

 the skin to disease. These family and individual normal 

 differences in the structure, functions, quality, and complexion 

 of the skin are everywhere known and recognised, so that 

 I need not here allude to them in any detail further than to 

 state that, caterts paribus, many of them predispose their 

 possessors to certain morbid dermatological conditions. 



It is well to remember at the outset that " there is nothing 

 essentially special in the details of cutaneous pathological 

 changes as compared with those which may occur in other 

 parts." 1 In other words, between the facts of general and 

 skin pathology there has recently been demonstrated such a 

 general similarity that the same appearance, changes, and 

 causes in morbid action are recognised in the diseases of the 

 integument, as in the pathological conditions of other parts 

 of the body. It is also necessary that the part played by 

 various concomitant conditions in each individual should be 

 estimated and appreciated, as these undoubtedly modify the 

 character and derivation of the particular disease that may 

 be present. 



Without attempting to give any detailed classification of 

 skin diseases infinite in their variety of forms, as multitu- 

 dinous in the names given to them I may be permitted to 

 roughly formulate them in the following ten groups, as given 

 by Dr. Tilbury Fox viz., the eruptions of the acute specific 

 diseases ; local inflammations ; diathetic diseases ; hyper- 

 and atrophic disease ; new formations ; hsemorrhagic, 



1 Dr. Tilbury Fox. 



