382 Itoi/al Society. 



but if we assume the mutual dependence of the refracting and reflect- 

 ing forces, then the experiments recorded in this paper will establish 

 a variation in the law of the refracting forces of different media. The 

 facts may be explained on the undulatorv theory of light, by sup- 

 posing that the density or elasticity of the ether varies near the sur- 

 face of different bodies, — an hypothesis which has already afforded an 

 explanation of the loss of part of an undulation in several of the phae- 

 nomena of interference ; the part lost being, according to Dr. Young, 

 a variable fraction depending on the nature of the contiguous media. 

 The phsenomena of periodical colours at the confines of media of 

 the same or of different refractive powers, are evidently dependent on 

 the law of interference ; although it may be difficult lo point out the 

 precise mode in which they are produced. In combinations where 

 there is much uncompensated refraction, their production is influenced 

 by certain changes, such as the formation of a thin and invisible film 

 on the surface of the solid, the nature and origin of which the author 

 endeavours to investigate, but which he acknowledges he has hitherto 

 been unable to discover. That some unrecognised physical principle 

 is the cause of all these phsenomena, will, he thinks, appear still more 

 probable from a paper which he intends to present to the Society, on 

 the production of the very same periods of colour at similar angles of 

 incidence by the surfaces of metals and transparent solids when acting 

 singly upon light. 



iVIarch 5. — A paper was read, intitled, " Anatomical description of 

 the foot of a Chinese female." By Bransby Blake Cooper, Esq. j 

 communicated by P. M. Roget, M.D. Sec. R.S. 



The foot, of which an account is here given, was obtained from the 

 dead body of a female found floating in the river at Canton, and had 

 all the characters of deform^ity consequent upon the prevailing habit 

 of early bandaging for the purpose of checking its natural growth. 

 To an unpractised eve it has more the appearance of a congenital 

 malformation, than of being the effect of art, however long continued j 

 and appears at first sight like a club foot, or an unreduced dislocation. 

 From the heel to the great toe the length of the foot measures only 

 four inches ; the great toe is bent abruptly backwards, and its ex- 

 tremity pointed directly upwards ; while the phalanges of the other 

 toes are doubled-in beneath the sole of the foot, having scarcely any 

 breadth across the foot where it is naturally broadest. The heel, in- 

 stead of projecting backwards, descends in a straight line from the 

 bones of the leg, and imparts a singular appearance to the foot, as if 

 it were kept in a state of permanent extension. From the doubling-in 

 of the toes into the ^ole of the foot, the external edge of the foot 

 is formed in a great measure by the extremities of the metatarsal 

 bones J and a deep cleft or hollow appears in the sole across its 

 whole breadth. The author gives a minute anatomical description of 

 all these parts, pointing out the deviations from the natural confor- 

 mation. He remarks, that from the diminutive size of the foot, 

 the height of the instep, the deficiency of bieadth, and the density 

 of the cellular texture, all attempts to walk with so deformed a 

 foot must be extremely awkward; and that in order to preserve an 



equilibrium 



