78 THE CHARTS — ^DISEASES OF THE EAR. 



quently taller, if we: admit the correlation of age and height,) if he have an incurable, 

 or, what amounts to the same thing, an uncured, disease, carries it, so to speak, with 

 him from one age to another, and, entering a new class, (by age,) he is joined by 

 others who, while in the preceding class or age were free from the disease, have now 

 contracted it. So through the different periods of age ; the men attacked when young 

 would, in a series of observations covering a life-time, count each time, and have their 

 numbers swelled by those more lately attacked. 



With curable diseases, however, the case is different ; for a man who in a preceding 

 class or period of age was affected by a certain curable disease, may be free from it 

 upon entering a succeeding one ; and, although new cases will be constantly occurring, 

 they will simply take the place of the cured ones, and not be added, as in the case of 

 incurable diseases. Tliis explanation may satisfactorily account for an increased 

 number of cases of incurable diseases found among the older men, and, allowing the 

 relation of age to height, for the increase with increase of height, also for the con- 

 stancy or very slight variation of the ratio for both age and height, as regards curable 

 diseases. But again, in favor of what has been termed the apparent explanation, we 

 find that certain diseases, noticeably diseases of the eye and of the ear, were found in 

 greatly-increased ratio among the older men, while the taller men were not more, and 

 in some instances were even less, affected than the shorter ones. 



In certain diseases, which, from their nature, result in an impeding of growth or 

 the lessening of stature, this condition would be a natural consequence, because a 

 man affected by such would be recorded among men of a less stature than he would 

 have attained to had he been free from disease ; but diseases of the eye or of the ear, 

 it is believed, have no such tendency. We can also readily account for the constancy — 

 that is, a want of increase in the ratio as regards age in certain incurable diseases — by 

 the fact that the older a man becomes the more likely is he to have two (or even more,) 

 diseases at the same time, and to be rejected on account of the one Avhich is gravest in 

 its character, or is most apparent. For instance, a man having amaurosis, and also 

 inguinal hernia, would undoubtedly be rejected on account of the hernia, because of 

 the ease with which it would be discovered, although the amaurosis would be not less 

 a cause for rejection. 



The liability to error which attends the hasty formation of opinions, or the found- 

 ing of theories upon isolated facts, unaccompanied by other testimony concun-ent or 

 conflicting, is thus demonstrated. The "balance of evidence" seems, however, to 

 indicate that, although there may be a correlation of height and susceptibility, or pre- 

 disposition to certain diseases, the very marked apparent relation is merely coincident 

 with the real correlation of age and height. 



CHART IX. 



DISEASES OP THE EAR. 



The general features of this and the preceding chart are so nearly the same that 

 the remarks upon the latter answer for both. Viewed, however, in relation to each 

 other, it may lie remarked thai the prevalence of diseases of the ear among the married 



