THE CHARTS INSANITY DISEASES OF THE EYE. 77 



as this ; but the deviation from the position which the hue ought to occupy is probably 

 too great to be accouuteil for in this manner. It may, however, be referred to the cause 

 mentioned in the remarks on chronic rheumatism, namely, to the superior vitality of 

 the " prime of life," which probably enables a man to keep off, or, rather, of itself 

 keeps off, an attack of paralysis until later in life. As sustaining this view, it will be 

 noticed that the increase for the next period of five years was very marked. A pause 

 in the increase of the disease with increase of height, amounting to almost a con-e- 

 sponding recession, evidences the relation of age to height, adverted to elsewhere. 



Owing to the very small number of cases, the division "Nativity" cannot be 

 said to furnish entirely reliable indications, except as regards the American, German, 

 Irish, and some other nativities, of which the number examined was large. 



CHART VII. 



INSANITY. 



The comments on the preceding chart apply, in the main, to this ; and many 

 points of interest which it is unnecessary to particularize will appear on inspection of 

 the chart. 



CHART VIII. 



DISEASES OF THE EYE. 



This chart shows the ratio of rejection on account of this class of diseases, which 

 includes diseases of the eyelids. 



The only noticeable departure from the general rules is found in the division 

 " Heiffht," where it will be seen that althoug-h the usual increase of the ratio with 

 increase of age occurs, no such increase was found as a concomitant of the increased 

 height of the men examined. 



This is so radically different from the facts shown in the chart on chronic rheu- 

 matism that it calls for elucidation and demands careful consideration. The apparent 

 explanation of this difference is as follows : The increase of chronic rheumatism with 

 increase of height, is proved by this chart (in which no such increase occurs,) to be 

 owing to a definite relation of the disease to height ; or, in other words, the taller a 

 man is, no matter what his age may be, the more likely is he to have chronic rheu- 

 matism, while diseases of the eye are common to, and prevail to about the same extent 

 among, men of all heights. 



But, as opposed to tliis explanation, it has been shown in the comments on chronic 

 rheumatism that men, at least native Americans, increase in stature even up to forty 

 years of age, and that the older men — that is, of those under consideration — were, as a 

 class, the taller men. Now, if this reasoning be admitted as satisfactorily accounting- 

 for the increase of chronic rheumatism with increase of height, how shall we account 

 for the absence of such increase of diseases of the eye 1 



It would appear that the increased prevalence of a disease among men of advanced 

 age must occur in the manner following: A young man growing older, (and conse- 



