204 RIGHTHANDEDNESS. 



and that the common centre of gravity of the body shifts more or less 

 towards the right, according to the greater or less inspiration of the 

 lungs, and the consequent inclination of the liver resulting from the 

 greater expansion of the right side of the chest. Herein may possibly 

 lie a slight predisposing cause leading to a preferential use of the right 

 side. But the evidence adduced altogether fails to account for what, 

 on such a theory, become abnormal deviations from the natural action 

 of the body. The position of the liver, and the influence of a full 

 inspiration, combine, according to Dr. Buchanan, to bring the centre of 

 gravity of the body nearly over the right foot. Hence in actively over- 

 coming a resistance from above, as when the carter bears up the shaft 

 of his cart on his shoulder, the muscular action originates mainly with 

 the lower limb of the same side, which partakes of the same muscular 

 power and development as the corresponding upper limb. On all such 

 occasions, where the muscular action is brought directly into play in 

 overcoming the weight or resistance. Dr. Buchanan affirms that the 

 right shoulder is much more powerful than the left ; but in the passive 

 bearing of weights it is otherwise. The very fact that the centre of 

 gravity lies on the right side, gives a mechanical advantage in. the use 

 of the left side in sustaining and carrying. burdens; and this assigned 

 pre-eminence of the left side and shoulder, as the bearer of burdens, is 

 accordingly illustrated by the Professor by means of an engraving, 

 representing " a burden borne on the left shoulder as the summit of 

 the mechanical axis passing along the right lower limb." 



Recent opportunities have afforded me a very practical means of 

 testing this question. While travelling in one of the large steamboats 

 on the Mississippi river, my attention was attracted by the deck-porters, 

 who at every landing are employed in transporting the freight to and 

 from the levee, and in supplying the vessel with cord-wood and coal. 

 They constitute, as a class, the rudest representatives of unskilled 

 labour, including both whites and negroes. For hours 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 cord-wood. Watch- 

 ing them closely, I observed that some gave the preference to the right 

 and some to the left shoulder in bearing their burden ; and this whether, 

 as with the bale and sack, they had it placed on the shoulder by others, 

 or with the cord-wood, which they loaded for themselves. Noting, 

 accordingly, in separate columns, the use of the right and left shoulder, 

 and in the case of loading with cord-wood the employment of the right 



