32 DANIEL WILSON ON THE RIGHT 
together they are to be seen going at a run to and from the lower deck of the vessel, 
carrying sacks of grain, bales, chests, or bundles of cordwood. Watching them closely, I 
- observed that some gave the preference to the right and some to the left shoulder in bear- 
ing their burden ; and this whether, as with bale and sack, they had it placed on their 
shoulders by others, or, as with cordwood, they took the load up themselves. Noting 
in separate columns the use of the right and left shoulder, and in the case of loading 
with cordwood the employment of the right and left hand, I found the difference did 
not amount to much more than sixty per cent. In one case I noted 137 carry the 
burden on the left shoulder to 81 on the right ; in another case 76 to 45; and in the case 
of loading cordwood, where the natural action of the right hand is to place the burden on 
the left shoulder, so that the use of the right shoulder necessarily implies that of the left | 
hand, the numbers were 65 using the left shoulder and 36 the right. Here, therefore, 
a practical test of a very simple yet reliable kind fails to confirm the idea of any such 
mechanical cause inherent in the constitution of the human frame, tending to a uniform 
exertion of the right side and the passive employment of the left, in muscular action. 
While thus questioning some of the assumptions and deductions set forth by Dr. 
Buchanan, it must be acknowledged that his later theory has this great advantage over 
other attemps to account for right-handedness that it equally meets the cases of deviation 
from prevalent usage. No theory is worthy of serious consideration which deals with 
left-handedness as an exceptional deviation from habitual action : as where, in his earlier 
treatise, Dr. Buchanan expressed the belief that many instances of left-handedness are 
“merely cases of ambidextrousness, when the habit of using the left side, in whatever 
way begun, has given to the muscles of that side such a degree of development as enables 
them to compete with the muscles of the right side, in spite of the mechanical disadvan- 
tages under which they labour.” “There is an awkwardness,” he added, “in the muscular 
efforts of such men, which seems to indicate a struggle against nature.” But for those 
indisputable cases of “men who unquestionably use their left limbs with all the facility 
and efficiency with which other men use their right,” he felt compelled either to resort to 
the gratuitous assumption of “ malformations and pathological lesions in early life, diseases 
of the right lung, contraction of the chest from pleurisy, enlargement of the spleen, dis- 
tortions of the spine,” etc.; or to assume a complete reversal of the whole internal organic 
structure. 
More recently, Dr. Humphry, of Cambridge, has discussed the cause of the prefer- 
ential use of the right hand, in his monograph on “ The Human Foot and Human Hand,” 
but with no very definite results. Many attempts, he says, have been made to answer 
the question, Why is man usually right-handed ? “ but it has never been done quite satis- 
factorily ; and I do not think that a clear and distinct explanation of the fact can be given. 
There is no anatomical reason for it with which we are acquainted. The only peculiarity 
that we can discern, is a slight difference in the disposition, within the chest, between 
the blood-vessels which supply the right and left arms. This, however, is quite insuffi- 
cient to account for the disparity between the two limbs. Moreover, the same disposition 
is observed in left-handed persons and in some of the lower animals; and in none of the 
latter is there that difference between the two limbs which is so general among men.” 
Dr. Humphry accordingly inclines to the view that the superiority of the right hand is 
not natural, but acquired. “ All men,” he says, “are not right-handed; some are left- 
