HEREDITARY DISEASE. 



taint. Privation, excesses, errors in habits of life, sedentary occupations, the 

 pernicious influence of certain trades, grief, anxiety, and the other wasters of vital 

 power, are undoubtedly important factors. The development of a constitutional 

 predisposition is favoured by those errors of life, those sins against natural laws 

 which we are all of us committing so frequently. To this class belong all excesses 

 which waste the vital powers ; undue carefulness and anxiety, over- watch ing, the 

 exciting race after wealth and distinction, and the ineffectual struggle against 

 poverty. The over-nursed in close and luxurious chambers; the student outstepping 

 his powers on a short Alpine holiday ; the sorely-taxed governess, toiling all day and 

 sitting up half the night to enjoy the luxury of solitude and converse with books 

 and absent friends ; the scantily-clad lady undergoing, in ill-ventilated rooms, the 

 dangerous excitement of the ball ; these are all labouring thoughtlessly to prepare 

 the way for the development of any latent but hereditary taint to which they may 

 be subject. 



Diseases that are hereditary usually make their appearance at a much earlier age 

 than when acquired. Gout, for instance, is extremely rare before the age of twenty, 

 but in cases of marked family predisposition it may be met even in boys at school. 

 The mistake is often made of supposing that because in a certain case a disease is 

 hereditary there is little or nothing to be done for it in the way of treatment. On 

 the contrary, so far from relaxing our efforts to effect a cure, we should treat it all 

 the more promptly and energetically. 



Strictly speaking, age cannot be said to constitute a predisposing cause of disease, 

 although it carries with it certain things which may be. We meet with people of 

 all ages who are free from illness and discomfort of any kind. It is not uncommon 

 to hear a man say that he has not had a day's illness for the last forty years. We 

 might conceive the possibility of a person passing from the cradle to the grave with- 

 out suffering from anything but the most trivial ailments. Practically, such instances 

 are not often met with, for at some point or other in the long course of life, the 

 chain of good succession is broken by a faulty link or an unexpected blow, and then 

 follow one or other of the many ills that make up the miseries of common life and 

 average health. 



Although age is not })er se a predisposing cause of disease, there are certain 

 disorders which are far more common at some periods of life than at others. In 

 infancy there is very little power of resistance, and a very slight disturbing force 

 will serve to upset the equilibrium of health. Infants have but little power of 

 maintaining the bodily temperature, and if exposed to cold suffer much more than 

 adults. Errors of diet readily irritate the delicate mucous membrane of their 

 stomach, and they are especially liable to suffer from diarrhoea. Then, again, the 

 process of teething is often accompanied by convulsions and other signs of marked 

 disturbance of the nervous system. In boyhood there is, on the one hand, the risk 

 of accident resulting from high animal spirit unrestrained by discretion, and 

 on the other the fear of excessive mental labour, as in working for examina- 

 tions and other objects of early ambition. Later on, when he comes of age, 

 he is anxious about his future prospects, about the profession or business 

 he is about to enter, and for which lie is preparing, and there are many 

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