SECONDAR Y EFFECTS OF DISEASE 269 



and they seem to throw a useful light on what is usually called 

 " the inheritance of disease." 



Inherited and Independent Variations. — It is hardly neces- 

 sary to point out that the occurrence of a particular predisposition 

 — ^whether it be to gout, to diabetes, or only to " freckling " 

 — may be interpreted either as the outcome of an inherited 

 germinal variation, or as an independent fresh variation similar 

 to one which occurred in ancestors, just as the occurrence of 

 great musical or mathematical talent may be interpreted either 

 as inherited peculiarity or as fresh variation. The facts seem 

 to show that certain variations have great staying-power through- 

 out generations, and also that nature often repeats herself. 

 Each case must be interpreted in terms of what is known of the 

 lineage. 



Inheritance of Secondary Effects of Disease. — In many cases 

 it seems legitimate, perhaps necessary, to suppose that a disease 

 in a parent may have a secondary effect on the germinal material, 

 and may prompt germinal variations which find expression 

 during the development of the offspring as diseases. 



In some forms of rheumatism there is what may be called a 

 poisoning— an auto-intoxication — of the living body with its 

 own waste-products — e.g. urates ; in some forms of bacterial 

 disease, as the popular phrase " blood-poisoning " suggests, the 

 same result is brought about by the waste-products or by- 

 products of the intruding microbes ; and it seems certain that 

 an equally thorough poisoning may be brought about by the 

 intemperate use of alcohol, ether, opium, etc. Even water- 

 drinkers may be in certain areas the victims of lead-poisoning, 

 for which they cannot reproach themselves. Experts may 

 differ as to the most accurate way of expressing the facts, but 

 it is certain that a man may thoroughly poison himself, for a 

 time at least, with alcohol, opium, tobacco, or the like. Organ 

 after organ may be injuriously affected ; the blood, the urine, 

 even the sweat will tell the tale, as it were in protest ; and even 



