NOVEMBEK 1, 1907] 



SCIENCE 



593 



pertaining to right-handedness, left-handed- 

 ness, etc. After a more extended study and 

 experience of the subject I recognize that I 

 made some errors and more omissions, and 

 these I may now correct. The terms right- 

 handed and left-handed are so firmly fixed in 

 the language, and so recognized as expressing 

 the unconscious choice and superior expert- 

 ness of one or the other hand for certain 

 tasks, that it is useless to attempt putting 

 them aside for more accurate words. Estab- 

 lished usage and habit make language and 

 govern the world. "Eight-handed," "left- 

 handed," etc., imply nothing of expertness, 

 etc., literally, but usage has put such mean- 

 ings into them. Terms merely localizing the 

 organs without added significance must 

 therefore be devised, e. g., dextral, sinistral, 

 dextromanualj dextrocular, and all the rest. 

 To extend the idea of expertness to the cor- 

 responding organs, right-eyed, left-eyed, right- 

 footed, right-eared, etc., may be used after 

 the analogy of right-handed. The words 

 amiidextral and ambidexterity should never 

 be used by sensible persons. No one has yet 

 existed with two dextral hands ; no left-handed 

 person has ever been trained to have an equal 

 proficiency or expertness of each hand for 

 all tasks ; it would be most undesirable and 

 wasteful of life to have such equal expert- 

 ness; all or most such attempted training 

 results in unhappiness, confusion, inexpert- 

 ness and disease; the right-handed, accord- 

 ing to the crazy theory, should be trained to 

 an equal and ludicrous sinistromanual ex- 

 pertness, etc. The violinist should bow or 

 finger equally expertly with each hand; the 

 pianist play upon a reversed keyboard, the 

 base notes to the right, half the time ; soldiers 

 should carry their guns and swords half the 

 time in the left hand, step -off with the right 

 foot first on alternate days; and all sewing, 

 writing, use of the knife and fork, handsha- 

 king, etc., done alternately with the sinistral 

 and the dextral hands, etc. 



As to right-eyedness, left-eyedness, etc., 

 there is a world of new facts coming to light 

 of profound importance, medically, surgically, 

 socially, and especially to the person abnormal 

 in these respects. In practical ophthalmology. 



" dominance " of the dextral eye in the right- 

 handed, and the preservation of it, or reestab- 

 lishment of it when lost (vice versa in the case 

 of the left-handed), is of vast import, possibly 

 to the life of many individuals. With divided 

 or alternate dominance one of my patients was 

 constantly making mistakes, confused, run- 

 ning into objects, steering his automobile into 

 collisions, etc. (The tests are many and 

 easily made : For instance, looking through the 

 held-up pencil or finger at the opposite wall, 

 an image, one image, of the pencil is seen by 

 the dominant eye — the dextral, of course, 

 normally, in the right-handed, the sinistral in 

 the left-handed. If the dextral is the domi- 

 nant eye, then by putting something over the 

 left, the image will not be displaced; if the 

 dextral eye is shut off, the image of the pencil 

 will " jump " to the right. If the sinistral 

 is the dominant eye, the reverse will take 

 place.) If two images are seen, then the 

 person has divided dominance or equidomi- 

 nance, and he is a patient, having confusions 

 of mind and action which may cause acci- 

 dents at any time, and which must decidedly 

 abnormalize him in many ways. Probably 

 equidominance is a half-way stage of the 

 change from normal to reversed dominancy. 

 It would be better that the right-handed 

 should have the sinistral eye dominant (vice 

 versa in the left-handed) than that he should 

 have equidominance. I have had four patients 

 reaching middle adult life who used one 

 hyperopic eye solely for distance-vision (i. e., 

 for objects over about two feet away), and the 

 other myopic eye solely for all vision in read- 

 ing, writing, etc. Of course the hjrperopic eye 

 in such cases (as in one of my patients), 

 although the left (in a right-handed person), 

 must become the dominant eye, because domi- 

 nance has existence and use only in distance- 

 seeing. 



The necessity for new terms to designate the 

 states and functions of attention comes to 

 view in the fact that civilization is creating a 

 new sort of consciousness and attention. The 

 old psychology considered that attention or 

 consciousness was to be likened to the passing 

 of single grains of sand through the con- 

 striction of the hour-glass. That view was 



