400 POPULAR SCIENCE MONTHLY. 



other minute particles of dust, while in the case of the tall headed boy 

 (Fig. 16) who has, by actual measurement, the visual plane adjusted 

 more than twenty degrees above the horizon, the larynx forms a hinge- 

 like valve and in the quiet eddies of a lung under these circumstances 

 the tubercle bacilli can easily hold high carnival. If the direction of 

 the large branches of the air tubes is considered it is evident that the 

 circulation of the air in the very upper portions of the lungs of one 

 with such a habitual pose would naturally be even less active than in 

 the lower parts, and it is interesting to remember that it is in the 

 upper lobes that the bacilli usually commence their inroads. The 

 modern treatment of consumption is fresh air. It is evident that the 

 amount of air admitted to the lungs of a person with the habitual 

 attitude of this boy must be very materially modified by this position 

 of the head; and could the normal pose be improved he would by that 

 means be subjected to the fresh-air treatment. It will be seen that 

 this is entirely practicable. 



The comparative immunity of the negro race from consumption has 

 already been referred to, and it is a fact of much practical interest 

 that among the people of Iceland, people with the extreme broad 

 head and with the characteristic pose, the head thrown back, the chin 

 elevated, consumption is unknown. Yet these people habitually inhale 

 the most vitiated atmosphere, an atmosphere which, habitually inhaled 

 by the people of this country, would induce an epidemic of con- 

 sumption which would be of the most devastating character. 



As the general pose of the head and the attitude of the body differ 

 in the class with high heads from those of the other classes, so the gait 

 and carriage of these people differ widely from those of the others. If 

 the cake walk is an extravagant exaggeration of the walk of the classes 

 with the low visual plane, the stoop of Shylock as it is represented 

 on the stage is the exaggeration of the carriage of the other class. 



This is but a most cursory glance at a most important subject; and 

 the affections and characteristics mentioned are but a group of those 

 whose name is legion and which have for their cause one or other of 

 these visual conditions. 



Several years ago attention was called by the writer of this article 

 to the one-sided carriage of the head of those who have the visual line 

 of one eye higher than that of the other. I will only refer to it here as 

 one of the elements in this interesting subject. 



The practical question which arises from the presentation of this 

 subject is: Can the direction of the visual axes be so modified in the 

 individual case as to change the pose of the head and body so as to 

 relieve the person from the results of his physical peculiarity? To this 

 an emphatic affirmative answer can be given. The eyes can be adjusted 

 for any desired plane by a safe and speedy procedure. It may be said 



