Scientific Intelligence. — Anthrojyology. 407 



needle, loaded at one end, and divided at the other to contain 

 the liquor, which is either red or blue: it draws blood at 

 every stroke. — Alexander's Travels, 



30. On the predominance of the Right Arm over the Left. — M 

 le Comte, in a memoir relative to the predominance of the right 

 arm over the left, in the Journal de Physiologic Experimentale 

 for January 1828, commences with refuting the opinion of those 

 who have attributed this predominance to habit. He then 

 passes under review the different hypotheses of physiologists, 

 who have hitherto looked for the cause of this phenomenon in 

 the normal organization of man, and finds all that has been pro- 

 posed inadequate. He at length comes to his own hypothesis. 

 In his opinion, the difference between the right and the left sys- 

 tem has its source in the position which the human fetus affects 

 in the uterus during the last months of gestation. In by far 

 the greater number of cases, the position is such that its left 

 arm and shoulder, as well as the left side in general, are pres- 

 sed against the bone of the pelvis. From this pressure there 

 results a contraction of the bloodvessels, a sort of atrophy com- 

 mencing in the whole left -system. The weakness of that side, 

 therefore, results from this congenital disposition. M. Comte, 

 with the view of obtaining a verification of his theory, compared 

 the cases in which the fetus occurs in the position which he con- 

 siders as calculated to determine the weakening of the left sys- 

 tem, with those in which it assumes a contrary position ; and he 

 has found a number which expresses the proportion of right- 

 handed and left-handed persons. Having been for several years 

 a resident pupil in the Maison Royale d''Accouchemens, M. 

 Comte occupied himself in observing the habits of the children 

 which, at the moment of their birth, he had supposed would be 

 left-handed, and he found his prognostications verified. He pro- 

 poses to make a further trial on the children placed in the Hos- 

 pice de Orphelins, with respect to whom it would be possible to 

 ascertain the peculiar circumstances that attended their birth. 

 He concludes with considerations respecting the means of en- 

 abling children to use both sides freely. To ensure this hap- 

 py result, it is not enough to make children use both hands 

 alike after they are two or three years old. To compensate the 

 defective condition of the left system at the moment of birth^ 



